Alcohol or aldehyde derivatives and their use

ABSTRACT

The present invention provides a cathepsin L inhibitor containing a compound of the formula: ##STR1## wherein R 1  is a hydrogen atom or an arylalkyl, heterocyclic-alkyl or lower alkyl group which may be substituted; R 2  and R 3  independently are a hydrogen atom or a hydrocarbon residue which may be substituted; R 4  is an alkanoyl, sulfonyl, carbonyloxy, carbamoyl or thiocarbamoyl group which may be substituted; X is formula: --CHO or --CH 2  OB (wherein B is a hydrogen atom or a protecting group of hydroxyl group); m and n independently are an integer of 0 or 1; provided that R 4  is an alkanoyl group substituted by aryl, a sulfonyl group substituted by aryl having more than 9 carbon atoms or by lower alkyl, or a carbamoyl or thiocarbamoyl group which may be substituted when R 1  is an unsubstituted lower alkyl, arylalkyl on methylthioethyl group, R 2  and R 3  independently are a lower alkyl or arylalkyl, X is --CHO, m is 1 and n is 0 or 1, or a salt thereof. 
     Compound (I) is useful as a prophylactic/therapeutic agent for osteoporosis.

This is a divisional of application Ser. no. 08/192,038 filed on Feb. 4,1994 and now U.S. Pat. No. 5,498,728.

FIELD OF THE INVENTION

The present invention relates to a cathepsin L inhibitor and boneresorption inhibitor containing an alcohol or aldehyde derivative, orsalt thereof as an active ingredient.

BACKGROUND OF THE INVENTION

Osteoporosis is a pathologic state or disease involving some symptom orrisk due to quantitative bone reduction exceeding a certain degree.Major symptoms are spinal kyphosis, fractures of dorsolumbar bones,vertebral centra, femoral necks, lower end of radius, ribs, upper end ofhumerus, and others. In normal bone tissue, bone breakdown occursconstantly, but there is good balance between bone formation andresorption; osteoblasts and osteoclasts play key roles in bone formationand bone resorption, respectively. Upon deterioration of this balance,bone resorption surpasses bone formation, resulting in quantitative bonereduction. Drugs suppressing bone resorption are therefore expected toserve well in preventing and treating osteoporosis. Traditionally, boneresorption-suppressing agents such as estrogens and calcitonin have beenused to treat osteoporosis. However, these therapeutic agents fail toachieve satisfactory effect in some cases, due to subject limitations oruncertain efficacy. There is therefore need of a newprophylactic/therapeutic method for accentuated bone resorption.

It has recently been shown that cathepsin L, a protease secreted byosteoclasts in the process of bone resorption, is involved in thedecomposition of collagen, a bone supporting protein. Epoxysuccinic acidderivatives, such as those disclosed in Japanese Patent UnexaminedPublication Nos. 304074/1990, 304075/1990 and 304085/1990 appear toexhibit cathepsin L inhibitory action. However, as disclosed in theabove patent publications, these epoxysuccinic acid derivatives inhibitnot only cathepsin L but also other proteases.

Traditionally, leupeptin and antipain have been known to inhibitprotease activity, and various compounds have been synthesized asaldehyde derivatives from amino acids. For example,acetyl-Leu-Leu-tryptophanal, acetyl-Leu-Leu-phenylalaninal etc. aredisclosed as chymotrypsin inhibitors in Biochemical and BiophysicalResearch Communications, Vol. 49, p. 343 (1972). Peptide-derivedphenylalaninal and tryptophanal derivatives are disclosed aschymotrypsin inhibitors and myodystrophy remedies in PCT Int. Appl. WO8400365. Also, PCT Int. Appl. WO 9214696 and PCT Int. Appl. WO 9204045disclose the anti-HIV activity of peptide-derived phenylalaninalderivatives and the CCK (cholecystokinin) antagonist activity ofN-acyltryptophanal, respectively. EP-A2-0 504 988 discloses a use forprophylaxis or treatment of bone disease of peptidic aldehydederivatives based on their hypocalcemic effect. However, thesereferences do not disclose peptide derivatives useful in the inhibitionof cathepsin L activity.

It would be desirable to have an agent that can be used to suppress boneresorption.

It would also be desirable to have an agent that is capable ofinhibiting cathepsin L activity without significantly inhibiting otherproteases.

It would further be desirable to have a method that can be used toreadily screen and select compounds that affect bone resorption.

SUMMARY OF THE INVENTION

The present inventors sought to develop a more commonly applicable drugshowing selective inhibition of cathepsin L and direct action on thebone to suppress bone resorption, and found that an alcohol and aldehydederivative represented by the following general formula (I) shows potentcathepsin L inhibition and direct action on the bone to excellentlysuppress bone resorption. The inventors made further investigationsbased on this finding, and developed the present invention.

Accordingly, the present invention relates to:

(1) a cathepsin L inhibitor containing a compound of the formula:##STR2## wherein R¹ is a hydrogen atom or an arylalkyl,heterocyclic-alkyl or lower alkyl group which may be substituted; R² andR³, independently are a hydrogen atom or a hydrocarbon residue which maybe substituted; R⁴ is an alkanoyl, sulfonyl, carbonyloxy, carbamoyl orthiocarbamoyl group which may be substituted; X is formula: --CHO or--CH₂ OB (wherein B is a hydrogen atom or a protecting group of hydroxylgroup); m and n independently are an integer of 0 or 1; provided that R⁴is an alkanoyl group substituted by aryl, a sulfonyl group substitutedby aryl having more than 9 carbon atoms or by lower alkyl or a carbamoylor thiocarbamoyl group which may be substituted when R¹ is anunsubstituted lower alkyl, arylalkyl or methylthiomethyl group, R² andR³ independently are a lower alkyl or arylalkyl group, X is --CHO, m is1 and n is 0 or 1, or a salt thereof,

(2) A bone resorption inhibitor containing the compound of the formula(I) or a salt thereof,

(3) A compound of the formula (I) or a salt thereof,

(4) The compound of (3) wherein R¹ is an indolyl-lower alkyl,

(5) The compound of (3) wherein R¹ is a naphthyl-lower alkyl,

(6) The compound of (3) wherein R¹ is a phenyl-lower alkyl,

(7) The compound of (3) wherein R¹ is a hydrogen or lower alkyl,

(8) The compound of (3) wherein R² is a branched lower alkyl,

(9) The compound of (3) wherein R² is a phenyl-lower alkyl,

(10) The compound of (3) wherein R³ is a branched lower alkyl,

(11) The compound of (3) wherein R³ is hydrogen,

(12) The compound of (3) wherein R⁴ is an alkanoyl, sulfonyl,carbonyloxy, carbamoyl or thiocarbamoyl group substituted by an alkyl,aryl, arylalkyl or alicyclic hydrocarbon group,

(13) The compound of (12) wherein R⁴ is an alkanoyl group substituted byaryl, a sulfonyl group substituted by aryl having more than 9 carbonatoms or by lower alkyl or a carbamoyl or thiocarbamoyl group which maybe substituted,

(14) The compound wherein X is --CHO or --CH₂ OH,

(15) The compound of (3) wherein m is 1 and n is 1,

(16) The compound of (3) wherein m is 1 and n is 0,

(17) The compound of (3) wherein m is 0 and n is 0,

(18) The compound of (3) wherein R¹ is a lower alkyl which may besubstituted by indolyl; R² is a lower alkyl; R⁴ is a naphthylsulfonyl ordibenzylacetyl; X is --CHO or --CH₂ OH; m is 0 or 1 and n is 0,

(19) A method of producing the compound as defined in (3) whichcomprises reacting a compound of the formula: ##STR3## wherein R² and R³independently are a hydrogen atom a hydrocarbon residue which may besubstituted; R^(4') is an alkanoyl, sulfonyl, carbonyloxy group whichmay be substituted, or its reactive derivative with a compound of theformula: ##STR4## wherein R¹ is a hydrogen atom or an arylalkyl,heterocyclic-alkyl or lower alkyl group which may be substituted, and ifdesired, subjecting to an oxidation reaction or a reaction of protectinga hydroxyl group, and

(20) A method of producing the compound as defined in (3) whichcomprises reacting a compound of the formula: ##STR5## wherein R² and R³independently are a hydrogen atom or a hydrocarbon residue which may besubstituted, M is a protecting group of amino group; m and nindependently are an integer of 0 or 1, or its reactive derivative witha compound of the formula: ##STR6## wherein R¹ is a hydrogen atom or anarylalkyl, heterocyclic-alkyl or lower alkyl group, subjecting todeprotecting reaction, to acylation, sulfonylation, oxycarbonylation,carbamoylation or thiocarbamoylation reaction in this order, and ifdesired, subjecting to an oxidation reaction or a reaction of protectinga hydroxyl group.

The present invention further includes methods for screening andselecting compounds that affect bone resorption.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a construction scheme for the plasmids obtained inExperimental Examples 4 and 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the present specification, the constituent amino acids are of theL-configuration, unless otherwise stated. When shown by abbreviations,their notation is in accordance with the IUPAC (International Union ofPure and Applied Chemistry)-IUB (International Union of Biochemistry)Biochemical Nomenclature, e.g., Gly for glycine, Leu for leucine and Ilefor isoleucine. Amino-protecting groups known to those skilled in theart are used. Preferable amino-protecting groups include acetyl,benzyloxycarbonyl, 4-methoxybenzyloxycarbonyl, t-butoxycarbonyl,phthalyl and formyl, with preference given to benzyloxycarbonyl ort-buthoxycarbonyl.

With respect to formula (I) above, the arylalkyl group for R¹, which maybe substituted for, is exemplified by phenyl, naphthyl, anthryl,phenanthryl and acenaphthylenyl, and monocyclic or condensed polycyclicaromatic hydrocarbon groups resulting from binding of an aromatichydrocarbon ring residue having 6 to 14 carbon atoms and a loweralkylene having 1 to 4 carbon atoms, such as benzyl, 2-phenylethyl,3-phenylpropyl, 2-phenylpropyl, 1-phenylpropyl, α-naphthylmethyl,α-naphthylethyl, β-naphthylmethyl and β-naphthylethyl etc.

The heterocyclic alkyl group for R¹, which may be substituted for, isexemplified by those resulting from binding of an aromatic heterocyclicring residue as exemplified below and a lower alkyl having 1 to 4 carbonatoms. The aromatic heterocyclic ring residue is exemplified by 5- to7-membered heterocyclic groups containing 1 atom of sulfur, nitrogen oroxygen, 5- to 6-membered heterocyclic groups containing 2 to 4 atoms ofnitrogen and 5- or 6-membered aromatic heterocyclic groups containing 1or 2 atoms of nitrogen and 1 atom of sulfur or oxygen. These aromaticheterocyclic groups may have condensed with a 6-membered ring containing2 or fewer atoms of nitrogen, a benzene ring or a 5-membered ringcontaining 1 atom of sulfur. Aromatic heterocyclic groups include2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidinyl, 4-pyrimidinyl,5-pyrimidinyl, 6-pyrimidinyl, 3-pyridazinyl, 4-pyridazinyl, 2-pyrazinyl,2-pyrrolyl, 3-pyrrolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl,3-pyrazolyl, 4-pyrazolyl, isothiazolyl, isoxazolyl, 2-thiazolyl,4-thiazolyl, 5-thiazolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl,1,2,4-triazol-3-yl, 1,2,3-triazol-4-yl, tetrazol-5-yl,benzimidazol-2-yl, indol-3-yl, 1H-indazolyl, benz b!furanyl,isobenzofuranyl, benz b!thienyl, 1H-pyrrolo 2,3-b!pyradin-2-yl,1H-pyrrolo 2,3-b!pyridin-6-yl, 1H-imidazo 4,5-b!pyridin-2-yl, 1H-imidazo4,5-c!pyridin-2-yl and 1H-imidazo 4,5-b!pyrazin-2-yl etc.

The lower alkyl group for R¹, which may be substituted for, isexemplified linear or branched C₁₋₆ alkyl group, such as methyl, ethyl,propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl,isopentyl, neopentyl, tert-pentyl, hexyl, 4-methylpentyl,1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl and 2-ethylbutyletc.

The aryl group or aromatic heterocyclic ring residue in the arylalkylgroup or aromatic heterocyclic alkyl group and lower alkyl group for R¹,which may be substituted for, may have 1 to 3 substituents at anypositions thereon. These substituents are exemplified by aliphatic chainhydrocarbon groups, alicyclic hydrocarbon groups, aryl groups, aromaticheterocyclic groups, non-aromatic heterocyclic groups, halogen atoms,nitro groups, amino groups which may be substituted for, acyl groupswhich may be substituted for, hydroxyl groups which may be substitutedfor, thiol groups which may be substituted for and carboxyl groups whichmay be esterified.

Such aliphatic chain hydrocarbon groups include linear or branchedaliphatic hydrocarbon groups such as alkyl groups, preferably thosehaving 1 to 10 carbon atoms, alkenyl groups, preferably those having 2to 10 carbon atoms, and alkynyl groups. Preferable alkyl groups includemethyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl,tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, 1-ethylpropyl,hexyl, isohexyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl,3,3-dimethylbutyl, 2-ethylbutyl, hexyl, pentyl, octyl, nonyl and decyl.Preferable alkenyl groups include vinyl, allyl, isopropenyl, 1-propenyl,2-methyl-1-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-ethyl-1-butenyl,3-methyl-2-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl,4-methyl-3-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl and5-hexenyl. Preferable alkynyl groups include ethynyl, 1-propynyl,2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl,3-pentynyl, 4-pentynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl and5-hexynyl etc.

Such alicyclic hydrocarbon groups include saturated or unsaturatedalicyclic hydrocarbons such as cycloalkyl groups, cycloalkenyl groupsand cycloalkadienyl groups. Preferable cycloalkyl groups includecyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl,cyclooctyl, bicyclo 2.2.1!heptyl, bicyclo 2.2.2!octyl, bicyclo3.2.1!octyl, bicyclo 3.2.2!nonyl, bicyclo 3.3.1!nonyl, bicyclo4.2.1!nonyl and bicyclo 4.3.1!decyl. Preferable cycloalkenyl groupsinclude 2-cyclopenten-1-yl, 3-cyclopenten-1-yl, 2-cyclohexen-1-yl and3-cyclohexen-1-yl. Preferable cycloalkadienyl groups include2,4-cyclopentadien-1-yl, 2,4-cyclohexadien-1-yl and2,5-cyclohexadien-1-yl etc.

Such aryl groups are monocyclic or condensed polycyclic aromatichydrocarbon groups, preferably phenyl, naphthyl, anthryl, phenanthryl,acenaphthylenyl and others, with preference given to phenyl, 1-naphthyl,2-naphthyl and others.

Preferable aromatic heterocyclic groups include aromatic monocyclicheterocyclic groups such as furyl, thienyl, pyrrolyl, oxazolyl,isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl,1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, furazanyl,1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,3,4-thiadiazolyl,1,2,3-triazolyl, 1,2,4-triazolyl, tetrazolyl, pyridyl, pyridazinyl,pyrimidinyl, pyrazinyl and triazinyl, and aromatic condensedheterocyclic groups such as benzofuranyl, isobenzofuranyl, benzob!thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl,benzoxazolyl, 1,2-benzisoxazolyl, benzothiazolyl, 1,2-benzisothiazolyl,1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl,quinoxalinyl, phthalazinyl, naphthylizinyl, purinyl, pteridinyl,carbazolyl, α-carbolinyl, β-carbolinyl, γ-carbolinyl, acridinyl,phenoxazinyl, phenothiazinyl, phenazinyl, phenoxthinyl, thianthrenyl,phenanthridinyl, phenanthrolinyl, indolizinyl, pyrrolo1,2-b!pyridazinyl, pyrazolo 1,5-a!pyridyl, imidazo 1,2-a!pyridyl,imidazo 1,5-a!pyridyl, imidazo 1,2-b!pyridazinyl, imidazo1,2-a!pyrimidinyl, 1,2,4-triazolo 4,3-a!pyridyl and 1,2,4-triazolo4,3-b!pyridazinyl etc.

Such halogens include fluorine, chlorine, bromine and iodine, withpreference given to fluorine and chlorine.

Such hydroxyl groups include the hydroxyl group and hydroxyl groupshaving an appropriate substituent, particularly a substituent for use asa hydroxyl-protecting group, such as alkoxy, alkenyloxy, aralkyloxy andacyloxy, as well as aryloxy. Said alkoxy is preferably an alkoxy having1 to 10 carbon atoms (e.g., methoxy, ethoxy, propoxy, isopropoxy,butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentoxy, isopentoxy,neopentoxy, hexyloxy, heptyloxy, nonyloxy, cyclobutoxy, cyclopentoxy,cyclohexyloxy). Said alkenyloxy is exemplified by those having 1 to 10carbon atoms such as allyloxy, crotyloxy, 2-pentenyloxy, 3-hexenyloxy,2-cyclopentenylmethoxy and 2-cyclohexenylmethoxy. Said aralkyloxy isexemplified by phenyl-C₁₋₄ alkyloxys (e.g., benzyloxy, phenethyloxy).Said acyloxy is preferably an alkanoyloxy having 2 to 4 carbon atoms(e.g., acetyloxy, propionyloxy, n-butyryloxy, isobutyryloxy). Saidaryloxy is exemplified by phenoxy and 4-chlorophenoxy.

Such thiol groups include the thiol group and thiol groups having anappropriate substituent, particularly a substituent for use as athiol-protecting group, such as alkylthio, aralkylthio and acylthio.Said alkylthio is preferably an alkylthio having 1 to 10 carbon atoms(e.g., methylthio, ethylthio, propylthio, isopropylthio, butylthio,isobutylthio, sec-butylthio, tert-butylthio, pentylthio, isopentylthio,neopentylthio, hexylthio, heptylthio, nonylthio, cyclobutylthio,cyclopentylthio, cyclohexylthio). Said aralkylthio is exemplified byphenyl-C₁₋₄ alkylthios (e.g., benzylthio, phenethylthio). Said acylthiois preferably an alkanoylthio having 2 to 4 carbon atoms (e.g.,acetylthio, propionylthio, n-butyrylthio, isobutyrylthio etc.).

Such amino groups include amino groups (--NH₂ groups) substituted for by1 or 2 of alkyl groups having 1 to 10 carbon atoms, alkenyl groupshaving 1 to 10 carbon atoms, aromatic groups and acyl groups (e.g.,methylamino, dimethylamino, ethylamino, diethylamino, dibutylamino,diallylamino, cyclohexylamino, phenylamino, N-methyl-N-phenylamino,acetylamino, propionylamino, benzoylamino etc.).

Such acyl groups include formyl and groups resulting from binding off analkyl having 1 to 10 carbon atoms, alkenyl having 1 to 10 carbon atomsor aromatic group and a carbonyl group (e.g., acetyl, propionyl,butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, hexanoyl, heptanoyl,octanoyl, cyclobutanoyl, cyclopentanoyl, cyclohexanoyl, cycloheptanoyl,crotonyl, 2-cyclohexenecarbonyl, benzoyl, nicotinoyl etc.).

Such esterified carboxyl groups (carbonyloxy groups) include thoseresulting from binding of a carboxyl group and an alkyl group having 1to 6 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl,propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl,sec-butoxycarbonyl, tert-butoxycarbonyl, pentoxycarbonyl andhexyloxycarbonyl, those resulting from binding of a carboxyl group andan alkenyl group having 3 to 6 carbon atoms, such as allyloxycarbonyl,crotyloxycarbonyl, 2-pentenyloxycarbonyl and 3-hexenyloxycarbonyl, andthose resulting from binding of a carbonyl group and an aralkyl groupsuch as benzyloxycarbonyl and phenetyloxycarbonyl.

With respect to formula (I) above, the hydrocarbon residue for R² or R³,which may be substituted for, is exemplified by arylalkyl groups whichmay be substituted for and aliphatic hydrocarbon groups which may besubstituted for. Such arylalkyl groups which may be substituted forinclude the same arylalkyl groups, which may be substituted for, asspecified for R¹ above. Such aliphatic hydrocarbon groups which may besubstituted for include linear or branched saturated aliphatichydrocarbon residues having 1 to 8 carbon atoms, such as methyl, ethyl,propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl,isopentyl, neopentyl, tert-pentyl, hexyl, isohexyl, heptyl and octyl,unsaturated aliphatic hydrocarbon residues having 2 to 8 carbon atoms,such as ethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl,3-butenyl, 2-methyl-1-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl,4-pentenyl, 3-methyl-2-butenyl, 1-hexenyl, 3-hexenyl, 2,4-hexadienyl,5-hexenyl, 1-heptenyl, 1-octenyl, ethynyl, 1-propynyl, 2-propynyl,1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl,4-pentynyl, 1-hexynyl, 3-hexynyl, 2,4-hexadiynyl, 5-hexynyl, 1-heptynyland 1-octynyl, saturated alicyclic hydrocarbon residues having 3 to 7carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyland cycloheptyl, unsaturated alicyclic hydrocarbon residues having 5 to7 carbon atoms, such as 1-cyclopentenyl, 2-cyclopentenyl,3-cyclopentenyl, 1-cyclohexenyl, 2-cyclohexenyl, 3-cyclohexenyl,1-cycloheptenyl, 2-cycloheptenyl, 3-cycloheptenyl and2,4-cycloheptadienyl, and groups which result from binding of one of theabove-mentioned alicyclic hydrocarbon residues and a saturated aliphatichydrocarbon residue and which have 4 to 9 carbon atoms, such ascyclopropylmethyl, cyclopropylethyl, cyclobutylmethyl,cyclopentylmethyl, 2-cyclopentenylmethyl, 3-cyclopentenylmethyl,cyclohexylmethyl, 2-cyclohexenylmethyl, 3-cyclohexenylmethyl,cyclohexylethyl, cyclohexylpropyl, cycloheptylmethyl andcycloheptylethyl.

The aliphatic hydrocarbon group for R² or R³, which may be substitutedfor, may have 1 to 3 substituents at any positions thereon. Thesesubstituents are exemplified by the same halogen atoms, nitro groups,amino groups which may be substituted for, acyl groups which may besubstituted for, hydroxyl groups which may be substituted for, thiolgroups which may be substituted for and carboxyl groups which may beesterified, as specified as substituents on the aryl or aromaticheterocyclic residue ring in the arylalkyl group or aromaticheterocyclic alkyl group for R¹, which may be substituted for.

The alkanoyl group, carbonyloxy group and sulfonyl group for R⁴ andR^(4') are represented by --COR⁵, --COOR⁶ and --SO₂ R⁷, respectively.The carbamoyl and thiocarbamoyl group for R⁴ are represented by CONHR⁸and --CSNHR⁹, respectively. (R⁵, R⁶, R⁷, R⁸ and R⁹, whether identical ornot, independently represent a hydrocarbon residue which may besubstituted for).

The hydrocarbon residue for R⁵, R⁶, R⁷, R⁸ or R⁹, which may besubstituted for, is exemplified by aliphatic hydrocarbon groups,aromatic hydrocarbon groups and heterocyclic groups. Such aliphatichydrocarbon groups are exemplified by the same examples as those givenabove for the aliphatic hydrocarbon group for R² or R³, which may besubstituted for. Such aromatic hydrocarbon groups are exemplified by thesame examples as those given above for the aryl group in the arylalkylgroup for R¹, R² or R³, which may be substituted for. Such heterocyclicgroups are exemplified by non-aromatic heterocyclic groups such asoxylanyl, azetidinyl, oxetanyl, thietanyl, pyrrolidinyl,tetrahydrofuryl, thiolanyl, piperizinyl, tetrahydropyranyl, morpholinyl,thiomorpholinyl, piperazinyl, homopiperizinyl, pyrrolinyl andimidazolizinyl, as well as by the same examples as those given above forthe aromatic heterocyclic residues on the aromatic heterocyclic alkylgroup for R¹, which may be substituted for. These non-aromaticheterocyclic groups may be condensed with a benzene ring, a 6-memberedring containing 2 or less atoms of nitrogen or a 5-membered ringcontaining 1 atom of sulfur. Specifically, such condensed non-aromaticheterocyclic groups include chromanyl, isochromanyl, thiochromanyl andisothiochromanyl. The aliphatic hydrocarbon groups, aromatic hydrocarbongroups and heterocyclic groups mentioned above to exemplify thehydrocarbon residue for R⁵, R⁶, R⁷, R⁸ or R⁹, which may be substitutedfor, may have 1 to 3 substituents at any positions thereon. Suchsubstituents are exemplified by the same examples as those given abovefor the substituent on the aryl group in the arylalkyl group for R¹,which may be substituted for.

With respect to X above, B for a protecting group of by hydroxyl groupin formula: --CHO or --CH₂ OB is exemplified those protecting groups ofhydroxyl group in the hydroxyl group as a substituent of lower alkylgroup of R¹ mentioned above, preferably alkanoyl group of 2 to 10 carbonatoms.

Regarding the protecting group of amino group represented by M, mentionis made those of amino-protecting groups disclosed herein before.

In the present invention, the salt of the compound of general formula(I) is preferably a physiologically acceptable salt, exemplified bysalts with inorganic bases, salts with organic bases, salts withinorganic acids, salts with organic acids and salts with basic or acidicamino acids. Preferable salts with inorganic bases include alkali metalsalts such as sodium salt and potassium salt, alkaline earth metal saltssuch as calcium salt and magnesium salt, aluminum salt and ammoniumsalt. Preferable salts with organic bases include salts withtrimethylamine, triethylamine, pyridine, picoline, ethanolamine,diethanolamine, triethanolamine, dicyclohexylamine andN,N'-dibenzylethylenediamine etc. Preferable salts with inorganic acidsinclude salts with hydrochloric acid, hydrobromic acid, nitric acid,sulfuric acid and phosphoric acid. Preferable salts with organic acidsinclude salts with formic acid, acetic acid, trifluoroacetic acid,fumaric acid, oxalic acid, tartaric acid, maleic acid, citric acid,succinic acid, malic acid, methanesulfonic acid, benzenesulfonic acidand p-toluenesulfonic acid etc. Preferable salts with basic amino acidsinclude salts with arginine, lysine and ornithine. Preferable salts withacidic amino acids include salts with aspartic acid and glutamic acid.

With respect to compound (I), R¹ is preferably C₁₋₆ alkyl which may besubstituted by indolyl or aryl, especially indol-3-ylmethyl,benzylmethyl, methyl, isopropyl, 1-naphthyl or the like, R² ispreferably branched C₃₋₆ alkyl, phenyl-C₁₋₆ alkyl or hydrogen atom,especially sec-butyl, benzyl, hydrogen atom or the like, R³ ispreferably branched C₃₋₆ alkyl, especially sec-butyl, hydrogen atom, R⁴is preferably those being lower (C₁₋₆) alkyl which may be substituted byaryl or alicyclic hydrocarbon-alkyl or aryl which may be substituted asrespective R⁵, R⁶, R⁷, R⁸ and R⁹, and is more preferably a C₂₋₆alkanoyl, sulfonyl, carbonyloxy, carbamoyl or thiocarbamoyl group whichis substituted by C₁₋₆ alkyl, aryl, arylalkyl or cycloalkyl, especiallyan alkanoyl group substituted by C₉₋₁₂ aryl or a sulfonyl, carbamoyl orthiocarbamoyl group substituted by aryl of more than 9 carbon atoms orC₁₋₆ alkyl. R^(4') is preferably those being lower (C¹⁻⁶) alkyl whichmay be substituted by aryl or alicyclic hydrocarbon-alkyl or aryl whichmay be substituted as respective R₅, R₆ and R₇, and is more preferably aC₂₋₆ alkanoyl, sulfonyl or carbonyloxy group which is substituted byC₁₋₆ alkyl, aryl, arylalkyl or cycloalkyl, especially an alkanoyl groupsubstituted by C₉₋₁₂ aryl or a sulfonyl group substituted by aryl ofmore than 9 carbon atoms or C₁₋₆ alkyl. X is preferably --CHO or --CH₂OH, m is preferably 0 or 1 and n is preferably 0.

Particularly preferable compounds of general formula (I) includeN-(4-toluenesulfonyl)-(L)-isoleucyl-(L)-tryptophanal,N-(t-butoxycarbonyl)-(L)-isoleucyl-(L)-tryptophanal,N-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-tryptophanal,N-(benzyloxycarbonyl)-(L)-isoleucyl-(L)-isoleucyl-(L)-tryptophanal,N-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-isoleucyl-(L)-tryptophanal,N-benzylcarbamoyl-(L)-isoleucyl-(L)-tryptophanal, N-(2-cyclohexylethyl)carbamoyl!-(L)-isoleucyl-(L)-tryptophanal,N-(3-trifluoromethylphenylcarbamoyl)-(L)-isoleucyl-(L)-tryptophanal,N-(2-propylpentanoyl)-(L)-tryptophanal,N-dibenzylacetyl-(L)-tryptophanal, N-dibenzylacetyl-(L)-phenylalanal,N-benzyloxycarbonyl-(L)-isoleucyl-(L)-phenylalanal,N-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-phenylalaninal,N-(1-naphthylsulfonyl)-(L)-isoleucylalanal,N-benzyloxycarbonyl-(L)-leucyl-(L)-leucylglycinal,N-(2-propylpentanoyl)-(L)-alanyl-(L)-tryptophanal,N-(2-propylpentanoyl)-(L)-valyl-(L)-tryptophanal,N-(1-naphthylsulfonyl)-(L)-isoleucyl)-(L)-tryptophanol,N-dibenzylacetyl-(L)-tryptophanol andN-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-alaninol.

Production methods for compound (I) are hereinafter described in detail.

Method A ##STR7## In the above formulas, the symbols have the samedefinitions as those shown above.

This oxidation is carried out by a known oxidizing reaction. Suchreactions include chromic acid oxidations such as Jones' oxidation,using chromium oxide-sulfuric acid-pyridine, Collins oxidation, usingchromium-pyridine complex, oxidation with pyridinium chlorochromate(PCC) and oxidation with pyridinium dichromate (PDC), oxidation withactivated DMSO and oxidation with oxoammonium salt.

In the case of an optically active configuration, this oxidation isadvantageously carried out by activated dimethyl sulfoxide (DMSO)oxidation. Activated DMSO oxidation is carried out in a solvent in thepresence of both DMSO and an electrophilic reagent. This solvent isexemplified by ethers such as ethyl ether, isopropyl ether,tetrahydrofuran and dioxane, aromatic hydrocarbons such as benzene,toluene and xylene, N,N-dimethylformamide (DMF), halogenatedhydrocarbons such as chloroform and dichloromethane, pyridine anddimethyl sulfoxide, chosen as appropriate according to the kind ofelectrophilic reagent. Methods of activated DMSO oxidation include thedicyclohexylcarbodiimide (DCC) method, the acetic anhydride method, thephosphorus pentoxide method, the chlorine method, the sulfurtrioxide-pyridine method, the keteneimine-enamine method and the mercury(II) acetate method, named according to the electrophilic reagent used.This oxidation is advantageously carried out by the sulfurtrioxide-pyridine method, in which oxidation is achieved using a sulfurtrioxide-pyridine complex as a DMSO activator reagent in the presence oftriethylamine. This reaction can also be carried out with dimethylsulfoxide as a solvent. The amount of triethylamine and sulfurtrioxide-pyridine complex used is 1 to 10 mol, preferably 2 to 5 mol permol of compound (I-1). Reaction temperature is -70° to 80° C.,preferably -20° to 40° C., reaction time being 0.5 to 10 hours.

Aldehyde derivative (I-2) thus obtained may be isolated and purified byknown means of separation and purification such as concentration,concentration under reduced pressure, solvent extraction,crystallization, recrystallization, redissolution and chromatography.

Starting material compound of the Method A can, for example, be producedas follows:

Method B ##STR8## In the above formulas, the symbols have the samedefinitions as those shown above.

In this method, compound (III) or its reactive derivative (or saltthereof) is reacted with compound (IV) or its derivative reactive at theamino group thereof (or salt thereof) to yield compound (I-3).Preferable derivatives of compound (IV) reactive at the amino groupthereof include Schiff's base type imino or enamine form tautomericisomers resulting from reaction of compound (IV) and a carbonyl compoundsuch as aldehyde or ketone, silyl derivatives resulting from reaction ofcompound (IV) and a silyl compound such as bis(trimethylsilyl)acetamide,mono(trimethylsilyl)acetamide or bis(trimethylsilyl)urea, andderivatives resulting from reaction of compound (IV) and phosphorustrichloride or phosgene. Preferable salts of compound (IV) and itsreactive derivatives are exemplified by the same acid adduct salts asspecified for compound (I) above.

Preferable derivatives of compound (III) reactive at the carboxyl groupthereof include acid halides, acid anhydrides, activated amides andactivated esters. Other preferable reactive derivatives include acidchlorides, acid azides, mixed acid anhydrides such as those with asubstituted phosphoric acid such as dialkylphosphoric acid,phenylphosphoric acid, diphenylphosphoric acid, dibenzylphosphoric acidor halogenated phosphoric acid, or with dialkylphosphorous acid,sulfurous acid, thiosulfuric acid or sulfuric acid, or with a sulfonicacid such as methanesulfonic acid, or with an aliphatic carboxylic acid,such as acetic acid, propionic acid, butyric acid, isobutyropivalicacid, pentanoic acid, isopentanoic acid or trichloroacetic acid, or withan aromatic carboxylic acid such as benzoic acid, symmetric acidanhydrides, activated amides with imidazole, 4-substitutional imidazole,dimethylpyrazole, triazole or tetrazole, activated esters such ascyanomethyl ester, methoxymethyl ester, dimethyliminomethyl ester, vinylester, propargyl ester, p-nitrophenyl ester, trichlorophenyl ester,pentachlorophenyl ester, mesylphenyl ester, phenylazophenyl ester,phenylthio ester, p-nitrophenyl ester, p-cresylthio ester,carboxymethylthio ester, pyranyl ester, pyridyl ester, piperidyl esterand 8-quinolylthio ester, and esters with N-hydroxy compounds such asN,N-dimethylhydroxylamine, 1-hydroxy-2-(1H)-pyridone,N-hydroxysuccinimide, N-hydroxyphthalmide and1-hydroxy-1H-benzotriazole. These reactive derivatives can be optionallychosen according to kind of compound (III) used. Preferable salts ofreactive derivatives of compound (III) include salts with bases,exemplified by alkali metal salts such as sodium salt and potassiumsalt, alkaline earth metal salts such as calcium salt and magnesiumsalt, ammonium salt, and organic base salts such as trimethylamine salt,triethylamine salt, pyridine salt, picoline salt, dicyclohexylamine saltand N,N-dibenzylethylenediamine salt. This reaction is normally carriedout in an ordinary solvent such as water, an alcohol such as methanol orethanol, acetone, dioxane, acetonitrile, chloroform, methylene chloride,ethylene chloride, tetrahydrofuran, ethyl acetate, N,N-dimethylformsmideor pyridine, but can be carried out in any other organic solvent, aslong as it does not interfere with the reaction. These ordinary solventsmay be used in mixture with water.

When compound (III) is used in the form of free acid or salt thereof,this reaction is preferably carried out in the presence of an ordinarycondensing agent such as N,N'-dicyclohexylcarbodiimide,N-cyclohexyl-N'-morpholinoethylcarbodiimide,N-cyclohexyl-N'-(4-diethylaminocyclohexyl)carbodiimide,N,N'-diethylcarbodiimide, N,N'-diisopropylcarbodiimide,N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide,N,N'-carbonylbis(2-methylimidazole),pentamethyleneketene-N-cyclohexylimine,diphenylketene-N-cyclohexylimine, ethoxyacetylene,1-alkoxy-1-chloroethylene, trialkyl phosphite, ethyl polyphosphate,isopropyl polyphosphate, phosphorus oxychloride,diphenylphosphorylazide, thionyl chloride, oxalyl chloride, a loweralkyl haloformate such as ethyl chloroformate or isopropylchloroformate, triphenylphosphine, 2-ethyl-7-hydroxybenzisoxazoliumsalt, 2-ethyl-5-(m-sulfophenyl)isoxazolium hydroxide intramolecularsalt, N-hydroxybenzotriazole,1-(p-chlorobenzenesulfonyloxy)-6-chloro-1H-benzotriazole, or what iscalled Wilsmeier's reagent as prepared by reaction ofN,N-dimethylformamide and thionyl chloride, phosgene, trichloromethylchloroformate or phosphorus oxychloride. This reaction may also becarried out in the presence of an inorganic or organic base such asalkali metal hydrogen carbonate tri(lower)alkylamine, pyridine,N-(lower)-alkylmorpholine or N,N-di(lower)alkylbenzylamine. Althoughreaction temperature is not subject to limitation, this reaction isnormally carried out under cooling to heating conditions.

Compounds (I-1) and (I-3) are converted to compound (I-4).

Method C ##STR9##

In the above formula, B is a protective group for hydroxyl group and theother symbols have the same definition as those shown above.

The reaction is conducted by reacting B--OH or its reactive derivativeor its salt with compound (I-1) or its salt. This reaction is conductedas the same manner as the reaction of compound (III) or its reactivederivative of carboxyl group with compound (IV).

Method D ##STR10## In the above formulas, L represents acarboxy-protecting group; the other symbols have the same definitions asabove.

The carboxy-protecting group for L is exemplified by protecting groupsin common use in the field of peptide synthesis, such as esterderivatives.

In this method, compound (V) or its derivative reactive at the carboxylgroup thereof (or salt thereof) is reacted with compound (VI) or itsderivative reactive at the amino group thereof (or salt thereof) toyield compound (VII), which is then subjected to a deprotecting reactionto remove the carboxy-protecting group to yield compound (III-1). Thereaction of compound (V) or its derivative reactive at the carboxylgroup thereof (or salt thereof) and compound (VI) or its derivativereactive at the amino group thereof (or salt thereof) is carried out inthe same manner as method B.

The deprotecting reaction of compound (VII) to remove itscarboxy-protecting group can be achieved by any common method of carboxyprotective group-removing reaction, such as deprotection by hydrolysis,reduction or Lewis acid. When the carboxy-protecting group is an ester,it can be removed by hydrolysis or deprotection using Lewis acid,preferably hydrolysis in the presence of a base or acid. Preferablebases include inorganic bases such as alkali metal hydroxides (e.g.,sodium hydroxide, potassium hydroxide), alkaline earth metal hydroxides(e.g., magnesium hydroxide, calcium hydroxide), alkali metal carbonates(e.g., sodium carbonate, potassium carbonate), alkaline earth metalcarbonates (e.g., magnesium carbonate, calcium carbonate), alkali metalbicarbonates (e.g., sodium bicarbonate, potassium bicarbonate), alkalimetal acetates (e.g., sodium acetate, potassium acetate), alkaline earthmetal phosphates (e.g., magnesium phosphate, calcium phosphate), alkalimetal hydrogen phosphates (e.g., disodium hydrogen phosphate,dipotassium hydrogen phosphate), and organic bases such astrialkylamines (e.g., trimethylamine, triethylamine), picoline,N-methylpyrrolidine, N-methylmorpholine, 1,5-diazabicyclo4,3,0!non-5-ene, 1,4-diazabicyclo 2,2,2!non-5-ene and 1,8-diazabicyclo5,4,0!-7-undecene. Hydrolysis using a base is often carried out in wateror a hydrophilic organic solvent or mixture thereof. Preferable acidsinclude organic acids (e.g., formic acid, hydrobromic acid, sulfuricacid).

This hydrolysis is normally carried out in an organic solvent, water ora mixture thereof. Reaction temperature, not subject to limitation, ischosen as appropriate according to kind of carboxy-protecting group andmethod of deprotection. Deprotection using a Lewis acid is achieved byreacting compound (VII) (or salt thereof) with a Lewis acid such as aboron trihalide (e.g., boron trichloride, boron trifluoride), a titaniumtetrahalide (e.g., titanium tetrachloride, titanium tetrabromide), analuminum trihalide (e.g., aluminum chloride, aluminum bromide) or atrihaloacetic acid (e.g., trichloroacetic acid, trifluoroacetic acid).This deprotecting reaction is preferably carried out in the presence ofa cation capturing agent (e.g., anisole, phenol) and normally carriedout in a solvent which does not interfere with the reaction, such as anitroalkane (e.g., nitromethane, nitroethane), an alkylene halide (e.g.,methylene chloride, ethylene chloride), diethyl ether or carbondisulfide. These solvents may be used in mixture.

Deprotection by reduction is preferably applied to removing theprotecting groups such as esters of haloalkyls (e.g., 2-iodoethyl,2,2,2-trichloroethyl) and esters of aralkyls (e.g., benzyl). Methods ofreduction for this deprotecting reaction include reduction with acombination of a metal (e.g., zinc, zinc amalgam) or a chromium compoundsalt (e.g., chromium (II) chloride, chromium (II) acetate) and anorganic or inorganic acid (e.g., acetic acid, propionic acid,hydrochloric acid), and ordinary catalytic reduction in the presence ofan ordinary metal catalyst (e.g., palladium-carbon, Raney nickel).Although reaction temperature is not subject to limitation, thisreaction is normally carried out under cooling, room temperature orheating conditions.

Method E ##STR11## In the above formulas, the symbols have the samedefinitions as those shown above.

In this method, compound (IX) or its activated derivative at thecarboxyl group thereof (or salt thereof) is reacted with compound (VIII)or its activated derivative at the amino group thereof (or salt thereof)to yield compound (X), which is then subjected to a deprotectingreaction to remove its carboxy-protecting group to yield compound(III-2). This method is carried out in the same manner as method D.

Method F ##STR12## In the above formulas, the symbols have the samedefinitions as those shown above.

In this method, compound (XI) (or salt thereof) is reacted with compound(VIII) (or salt thereof) to yield compound (XII), which is thensubjected to a deprotecting reaction to remove its carboxy-protectinggroup to yield compound (III-3). The reaction of compounds (VIII) with(XI) is carried out in an appropriate solvent. This solvent isexemplified by aromatic hydrocarbons such as benzene, toluene andxylene, ethers such as dioxane, tetrahydrofuran and dimethoxyethane,alcohols such as methanol, ethanol and propanol, ethyl acetate,acetonitrile, pyridine, N,N-dimethylformamide, dimethyl sulfoxide,chloroform, dichloromethane, 1,2-dichloroethane,1,1,2,2-tetrachloroethane, acetone, 2-butanone and mixtures thereof.

The reaction of compounds (VIII) with (XI) is carried out in thepresence of an appropriate base exemplified by alkali metal salts suchas sodium hydroxide, potassium hydroxide, potassium carbonate, sodiumcarbonate and sodium hydrogen carbonate, amines such as pyridine,triethylamine and N,N-dimethylaniline, sodium hydride and potassiumhydride. The amount of these bases used is preferably about 1 to 5 molper mol of compound (VIII). The reaction is carried out at temperaturesof normally from -20° to 150° C., preferably from about -10° to 100° C.Compound (XII) thus obtained is subjected to a deprotecting reaction toyield compound (III-3). This deprotection is carried out in the samemanner as the deprotecting reaction in method D.

Method G ##STR13## In the above formulas, the symbols have the samedefinitions as those shown above.

In this method, compound (XIII) (or salt thereof) is reacted withcompound (XI) (or salt thereof) to yield compound (III-2). Thissulfonylation is normally carried out under what is called SchottenBaumann's conditions, in which amino acid derivative (XIII), prepared asa sodium salt in an aqueous solution, is reacted with compound (XI) andthen acidified.

Method H ##STR14## In the above formulas, the symbols have the samedefinitions as those shown above.

In this method, compound (XIII) (or salt thereof) is reacted withcompound (XIV) (or salt thereof) to yield compound (III-4). Thisacylation is carried out in the same manner as method G.

Method I ##STR15## In the above formulas, the symbols have the samedefinitions as those shown above.

In this method, compound (XIII) (or salt thereof) is reacted withcompound (XV) (or salt thereof) to yield compound (III-5). This methodis carried out in the same manner as method H.

Method J ##STR16## In the above formulas, the symbols have the samedefinitions as those shown above.

In this method, compound (VIII) (or salt thereof) is reacted withcompound (XVI) to yield compound (XVII), which is then subjected to adeprotecting reaction to remove its carboxy-protecting group to yieldcompound (III-5). The reaction of compound (VIII) (or salt thereof) andcompound (XVI) is carried out in an appropriate solvent. This solvent isexemplified by aromatic hydrocarbons such as benzene, toluene andxylene, ethers such as dioxane, tetrahydrofuran and dimethoxyethane,ethyl acetate, acetonitrile, pyridine, N,N-dimethylformamide, dimethylsulfoxide, chloroform, dichloromethane, 1,2-dichloroethane,1,1,2,2-tetrachloroethane, acetone, 2-butanone and mixtures thereof. Theamount of compound (XVI) used is preferably about 1 to 5 mol per mol ofcompound (VIII). The reaction is normally carried out at temperatures of-20° to 150° C., preferably about -10° to 100° C. Compound (XVII) thusobtained is subjected to a deprotecting reaction to yield compound(III-6). This deprotection is carried out in the same manner as thedeprotection in method D.

Method K ##STR17## In the above formulas, the symbols have the samedefinitions as those shown above.

In this method, compound (VIII) (or salt thereof) is reacted withcompound (XVIII) to yield compound (XIX), which is then subjected to adeprotecting reaction to remove its carboxy-protecting group to yieldcompound (III-7). This reaction is carried out in the same manner asmethod J.

Starting material compound (I-1) for methods A and C can also beproduced as follows:

Method L ##STR18## In the above formulas, M represents anamino-protecting group; the other symbols have the same definitions asthose shown above.

The amino-protecting group for M is exemplified by protecting groups incommon use in the field of peptide synthesis, such as oxycarbonylderivatives, with preference given to benzyloxycarbonyl.

In this method, compound (XX) or its derivative reactive at the carboxylgroup thereof (or salt thereof) is reacted with compound (IV) or itsderivative reactive at the amino group thereof (or salt thereof) toyield compound (XXI), which is then subjected to a deprotecting reactionto remove its amino-protecting group to yield compound (XXII). Thereaction of compound (XX) or its derivative reactive at the carboxylgroup thereof (or salt thereof) with compound (IV) or its derivativereactive at the amino group thereof (or salt thereof) is carried out inthe same manner as method B. In the amino-protecting group removingreaction of compound (XXI), the amino-protecting group can be removed byany commonly used method of reaction to remove the amino-protectinggroup. For example, the benzyloxycarbonyl group is removed by catalyticreduction in the presence of a commonly used metal catalyst (e.g.,palladium-carbon, Raney nickel). Reaction temperature is not subject tolimitation; the reaction is normally carried out under cooling, roomtemperature or heating conditions. Then, compound (XXII) is acylated inthe same manner as fie reaction of compounds (VIII) and (IX) in method Eor the reaction of compounds (XIII) and (XIV) in method H, sulfonylatedin the same manner as the reaction of compounds (VIII) and (XI) inmethod F, then oxycarbonylated in the same manner as the reaction ofcompounds (XIII) and (XV) in method I, carbamoylated in the same manneras the reaction of compounds (VIII) and (XVI) in method J, and thenthiocarbamoylated in the same manner as the reaction of compounds (VIII)and (XVIII) in method K, to yield compound (I-1).

In the present invention, the compound of formula (I) can beadministered orally or parenterally, as formulated by admixing aneffective dose with a physiologically acceptable carrier, excipient ordiluent in the form of solid preparations such as tablets, capsules,granules and powders, or liquid preparations such as syrups andinjectable preparations.

Pharmaceutically acceptable carriers are various organic or inorganiccarrier substances in common use as pharmaceutical materials, includingexeipients, lubricants, binders and disintegrating agents for solidpreparations, and solvents, dissolution aids, suspending agents,isotonizing agents, buffers and soothing agents for liquid preparations.Other pharmaceutical additives such as preservatives, antioxidants,coloring agents and sweetening agents may be used as necessary.Preferable excipients include lactose, sucrose, D-mannitol, starch,crystalline cellulose and light silicic anhydride. Preferable lubricantsinclude magnesium stearate, calcium stearate, talc and colloidal silica.Preferable binders include crystalline cellulose, sucrose, D-mannitol,dextrin, hydroxypropyl cellulose, hydroxypropylmethyl cellulose andpolyvinylpyrrolidone. Preferable disintegrating agents include starch,carboxymethyl cellulose, carboxymethyl cellulose calcium,crosscalmellose sodium and carboxymethyl starch sodium. Preferablesolvents include water for injection, alcohol, propylene glycol,macrogol, sesame oil and corn oil. Preferable dissolution aids includepolyethylene glycol, propylene glycol, D-mannitol, benzyl benzoate,ethanol, tris-aminomethane, cholesterol, triethanolamine, sodiumcarbonate and sodium citrate. Preferable suspending agents includesurfactants such as stearyltriethanolamine, sodium lauryl sulfate,laurylaminopropionic acid, lecithin, benzalkonium chloride, benzethoniumchloride and monostearic glycerol, and hydrophilic polymers such aspolyvinyl alcohol, polyvinylpyrrolidone, carboxymethyl cellulose sodium,methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose andhydroxypropyl cellulose. Preferable isotonizing agents include sodiumchloride, glycerol and D-mannitol. Preferable buffers include buffersolutions of phosphates, acetates, carbonates and citrates. Preferablesoothing agents include benzyl alcohol. Preferable preservatives includep-oxybenzoic acid esters, chlorobutanol, benzyl alcohol, phenethylalcohol, dehydroacetic acid and sorbic acid. Preferable antioxidantsinclude sulfites and ascorbic acid.

The compound of formula (I) potently inhibits cathepsin L, excellentlysuppresses bone resorption and is of low toxicity. The compound ofgeneral formula (I) can therefore be used to prevent or treatosteoporosis in mammals (e.g., mice, rats, rabbits, dogs, cats, bovines,swines, humans).

When using as a prophylactic/therapeutic agent, compound (I) (or saltthereof) is administered at 1 to 500 mg, preferably 10 to 200 mg dailyfor each adult in the case of oral administration.

The compound of formula (I) can also be used in a simple in vitro assayfor screening and selecting compounds that affect bone resorption. Thescreening method involves adding a compound of formula (I) to an invitro assay suitable for measuring bone resorption, such as the methodof Raisz Journal of Clinical Investigation, 44, 103-116 (1965)!. Theinhibition of bone resorption by the compound of formula (I) isrecorded. (Experimental Example 9 below, sets out the details of such anassay.) The test compound is then added to the assay and bone resorptionis again measured. Test compounds can include, for example, proteins,chemicals or drugs. Any changes in the bone resorption inhibitoryactivity of the compound of formula (I) would indicate that the testcompound has an influence on bone resorption. Such compounds may then befurther evaluated.

The action of compound (I) is hereinafter described by means of thefollowing experimental examples.

Experimental Example 1

Cloning of cathepsin L cDNA of human renal origin

To amplify human cathepsin L cDNA by the PCR method, four primers weresynthesized in accordance with a reported base sequence of cathepsin Lof human renal origin S. Gal and M. M. Gottesman, Biochem. J., 253, 303(1988)! as follows:

Sense primer No. 1: ##STR19##

3 μl of a solution of the human renal cDNA library λgt11 (CLONTECHLaboratories, Inc.) and 50 μl of distilled water were mixed. Afterincubation at 95° C. for 5 minutes, the mixture was immediately cooledin ice. Two primers (Nos. 1 and 3 above, 50 pmol of each) were added,and PCR was carried out as directed in the instruction manual for thekit supplied from Cetus/Perkin-Elmer, in which a series of reactions at94° C. for 1 minute, 55° C. for 2 minutes and 72° C. for 3 minutes wasrepeated in 50 cycles. To the reaction mixture were added two otherprimers (Nos. 2 and 4 above, 50 pmol of each), and PCR was carried outin the same manner as above. The PCR product was separated byelectrophoresis on 1.2% agarose gel; an amplified DNA fragment was seenat a position corresponding to the size (1132 bp) expected from the basesequence of cathepsin L of human renal origin. This DNA fragment wasrecovered from the gel and subcloned to the plasmid vector pBluescript®II SK+ (produced by STRATAGENE). The base sequence of the cDNA portion,determined by the dideoxynucleotide synthetic chain termination methodJ. Messing et al., Nucleic Acids Res., 9, 309 (1981)!, proved identicalwith the reported sequence. The plasmid containing this cDNA fragmentwas named pHCL-5.

Experimental Example 2

Expression of human cathepsin L in Escherichia coli MM294(DE3)

The cDNA of Experimental Example 1 was cleaved with restriction enzymeEcoRI and a 798 bp fragment (which encodes a part of the human cathepsinL precursor and the whole matured human cathepsin L) was recovered. Toboth ends of this fragment was ligated a BamHI linker(5'-pCCCGGATCCGGG-3'; sequence ID No. 5); the ligation product wasinserted to the plasmid vector pET-3c for expression in Escherichia coliMethods in Enzymology, ed. D. V. Goeddel, 185, 68, Academic Press(1990)!. The thus-constructed plasmid was designated pET-HCLα.Escherichia coli MM294(DE3) was transformed with pET-HCLα to expresshuman cathepsin L in the presence of the T7 promoter Methods inEnzymology, 185, 60 (1990)!. The thus-obtained Escherichia colitransformant Escherichia coil JM109/pTBN-HCLneo, harboring the plasmidpTBN-HCLneo, has been deposited under accession number IFO 15341 at theInstitute for Fermentation, Osaka, since Jun. 12, 1992, and underaccession number FERM BP 3897 at the Fermentation Research Institute,Agency of Industrial Science and Technology since Jun. 22, 1992.! wascultured; cells were disrupted by sonication and subjected to SDS-PAGE;a unique band appeared near 30 kDal, corresponding to human cathepsin L.Since the expressed product formed an inclusion body, human cathepsin Lwas partially purified from the precipitated fraction of theultrasonically disrupted transformant.

Experimental Example 3

Preparation of antiserum to recombinant human cathepsin L

The partially purified recombinant human cathepsin L described inReference Example 2 was mixed with an equal volume of Freund's completeadjuvant and about 1 ml was inoculated to a rabbit. Later, a mixture ofa partially purified human cathepsin L and an equal volume of Freund'sincomplete adjuvant was injected thrice at 10-day intervals, and bloodwas collected seven days after final injection. The obtained blood waskept standing at 37° C. for 30 minutes and then at 4° C. overnight,after which it was centrifuged to yield a human cathepsin L antiserum.

Experimental Example 4

Preparation of recombinant DNA for expression of human cathepsin L genein animal cells

After the plasmid pHCL-5 (described in Experimental Example 1) wasdigested with restriction enzyme BamHI, a fragment of human cathepsin LcDNA was recovered by agarose gel electrophoresis. Next, this cDNAfragment was inserted to the restriction enzyme BglII site of the vectorpTB551 for transient expression in animal cells prepared by convertingthe EcoRI site to BglII site in the plasmid pTB389 described by Ono etal. in Science, 236, 1116 (1989)! by the action of T4 DNA ligase andATP, to yield the expression plasmid pTB-HCL. MuLV-LTR was insertedbetween the restriction enzyme HindIII and ClaI sites of pTB-HCL toyield the expression plasmid pTBN-HCL (FIG. 1).

Experimental Example 5

Preparation of recombinant DNA for expression of human cathepsin L genein animal cells

To obtain an animal cell line that stably expresses human cathepsin L,the drug resistance marker neogene was inserted to the vector pTBN-HCLdescribed in Experimental Example 4 as follows: Namely, a fragmentcomprising the SV40 early promoter and the neo gene was inserted betweenthe restriction enzyme ClaI and SalI sites of the plasmid pTBN-HCL toyield the plasmid pTBN-HCLneo (FIG. 1).

Experimental Example 6

Expression of human cathepsin L gene in animal cells

Using the plasmid described in Experimental Example 5 (pTBN-HCLneo),mouse myeloma Sp2/0 cells were transformed as follows: Sp2/0 cells,cultivated in an ASF104 medium supplemented with 5% FCS (5% FCS/ASFmedium), were suspended in PBS(-) the same as Dullbecco's PBS but CaCl₂and MgCl₂ are removed! to adjust 1×10⁷ cells/ml. 500 μl of thissuspension was injected to a cuvette, 10 μg of said plasmid DNA wasadded, and the mixture was kept standing on ice for 5 minutes. Thisliquid was pulsated at 125 μF and 300 V, using a gene pulsar (producedby Bio-Rad Laboratories), and then again kept standing on ice for 10minutes. This liquid was transferred to 10 ml of 5% FCS/ASF104 mediumand cultured at 37° C. in the presence of 5% carbon dioxide. Forty-eighthours later the culture was transferred to a selection medium (5%FCS/ASF104 medium containing 200 fg/ml G418) and cultured on a 24-wellplate for 2 weeks. A number of colonies emerged, each of which wastransferred to an ASF104 medium containing 200 μg/ml G418 and cultured,followed by Western blot analysis of the culture supernatant using thehuman cathepsin L antiserum prepared in Experimental Example 3. Inresponse to the antiserum, unique bands appeared having molecularweights of about 40,000 to 30,000 and lower molecular weights; they wereidentified as a precursor of human cathepsin L and processing productsthereof, as estimated from their molecular weights. The culturesupernatant was assayed for cathepsin L enzyme activity, in accordancewith the method of A. J. Barrett and H. Kirschke Methods in Enzymology,80, 535 (1981)!; human cathepsin L activity was detected.

These findings confirm that transformed mouse myeloma cells expressingcathepsin L were obtained; these were designated as mouse myelomaSp-HCL26.

Experimental Example 7

Purification of human cathepsin L

The strain obtained in Experimental Example 6, showing high expressionof cathepsin L, (mouse myeloma Sp-HCL26, transformed with the plasmidpTBN-HCLneo, has been deposited under accession number IFO 50371 at theInstitute for Fermentation, Osaka (IFO) since Jun. 16, 1992 and underaccession number FERM BP 3902 at the Fermentation Research Institute(FRI), Agency of Industrial Science and Technology since Jun. 24, 1992),was cultured in 20 ml of an ASF104 medium supplemented with 10% FCS and200 μg/ml G418, after which it was transferred to 50 ml of a serum-freeselection medium (ASF104 medium supplemented with 200 μg/ml G418) andcultured for 5 days. After the culture supernatant was applied to acolumn of CM-Sephadex C-50 (25×4.4 cm), the column was washed withbuffer A (20 mM sodium acetate, 1 mM EDTA, pH 5.5), followed by elutionon a sodium chloride (NaCl) density gradient from 0 to 1M, to elutehuman cathepsin L near an NaCl concentration of about 0.4M. Thisfraction was applied to a Mono S column (HR5/5) of an FPLC system(produced by Pharmacia), followed by column washing and human cathepsinL elution in the same manner as above. The human cathepsin L fraction,eluted near an NaCl concentration of about 0.36M, was concentrated toyield a purified preparation.

Experimental Example 8

Determination of human cathepsin L inhibitory activity

The recombinant human cathepsin L purified in Experimental Example 7 wasdiluted with a diluent 0.1% Brij 35 (produced by Sigma ChemicalCompany)! to a concentration of 1 μg/ml. To 1 μl of this enzymedilution, 46 μl of the diluent, 2 μl of 0.1M DTT and 25 μl of anactivator/buffer (340 mM sodium acetate, 60 mM acetic acid, 4 mMdisodium EDTA, pH 5.5) were added. To this mixture were added a 1 μlsample, diluted to 10⁻² M with dimethyl sulfoxide (DMSO), and 25 μl of20 μM Z-Phe-Arg-NMec (enzyme substrate solution), followed by incubationat 30° C. for 10 minutes, after which 100 μl of a reaction stopper (100mM sodium monochloroacetate, 30 mM sodium acetate, 70 mM acetic acid, pH4.3) was added. This reaction was carried out on a 96-well fluoropiate(produced by Labo Systems).

After the reaction was stopped, the fluorescence intensity of freeaminomethylcoumarin was determined at a wavelength of 450 nm (excitationwavelength=365 nm), using a fluorometer FCA (produced by Baxter). For acontrol, 1 μl of sample-free DMSO was added instead; the fluorometricvalue obtained from this control reaction was taken as 100% activity.When the residual activity was not higher than 10%, the sample solutionwas further diluted and then assayed for residual activity in the sameprocedure as above to obtain the IC₅₀ value. The results are given inTable 1.

                  TABLE 1                                                         ______________________________________                                                        Cathepsin L Inhibitory Activity                               Compound (Example No.)                                                                         IC.sub.50 Value (M)!                                         ______________________________________                                        101             2.2 × 10.sup.-9                                         102             3.3 × 10.sup.-9                                         103             1.9 × 10.sup.-9                                         107             1.1 × 10.sup.-8                                         108             5.4 × 10.sup.-9                                         109             1.0 × 10.sup.-8                                         110             1.6 × 10.sup.-8                                         111             1.4 × 10.sup.-9                                         112             3.8 × 10.sup.-7                                         114             6.1 × 10.sup.-9                                         115             4.8 × 10.sup.-8                                         117             2.0 × 10.sup.-9                                         118             2.2 × 10.sup.-7                                         122             3.2 × 10.sup.-8                                         124             5.3 × 10.sup.-9                                         128             1.9 × 10.sup.-9                                         129             8.5 × 10.sup.-9                                         132             9.9 × 10.sup.-9                                         135             1.0 × 10.sup.-9                                         143             1.7 × 10.sup.-9                                         144             2.4 × 10.sup.-9                                         150             6.1 × 10.sup.-9                                         153             3.1 × 10.sup.-9                                         154             .sup. 9.5 × 10.sup.-10                                  158             1.4 × 10.sup.-9                                         167             4.3 × 10.sup.-8                                         168             2.6 × 10.sup.-8                                         175             1.9 × 10.sup.-8                                         188             3.7 × 10.sup.-8                                         190             5.5 × 10.sup.-8                                         191             4.7 × 10.sup.-9                                         192             4.2 × 10.sup.-9                                         193             3.9 × 10.sup.-9                                         ______________________________________                                    

Experimental Example 9

Bone resorption suppressing action

Bone resorption was measured by the method of Raisz Journal of ClinicalInvestigation, 44, 103-116 (1965)!. Specifically, one Sprague-Dawleyrat, at 18 days of gestation, was given 50 μCi of ⁴⁵ Ca (calciumisotope, in CaCl₂ solution) by subcutaneous injection. On the followingday, the animal was laparotomized and fetal rats aseptically removed.Both forearm bones (radius and ulna) were cut out from the body of eachfetus under an anatomical microscope, and connective tissue andcartilages were removed to the maximum possible extent, to prepare boneculture samples. Each bone fragment was pre-cultured at 37° C. for 24hours in 0.6 ml of BGJb medium (Fitton-Jackson modification, GIBCOLaboratories, United States) prepared by adding bovine serum albumin(final concentration 2 mg/ml), after which it was transferred to thesame medium as above but containing each compound (final concentration10 μg/ml or 10 μM) and cultured for two more days. ⁴⁵ Ca radioactivityin the medium and ⁴⁵ Ca radioactivity in the bone were then measured,and the percent ratio of ⁴⁵ Ca released from the bone to the medium wascalculated using the following equation: ##EQU1##

For control, bone fractions from fetuses of the same litter werecultured for two days in the absence of the test compound. The mean qstandard deviation for the values from five bone fragments in each groupwere calculated, and their percent ratios to the control werecalculated. The results are given in Table 2.

                  TABLE 2                                                         ______________________________________                                                              Bone Resorption                                         Compound  Concentration of                                                                          Inhibitory Activity  .sup.45 Ca                         (Example No.)                                                                           Compound    Release Rate (Percent to Control)!                      ______________________________________                                         3        10 μg/ml 49                                                       26       10 μM    79                                                       38       10 μM    76                                                       59       10 μM    67                                                       84       10 μM    74                                                      103       10 μg/ml 49                                                      108       10 μg/ml 42                                                      109       10 μg/ml 38                                                      110       10 μg/ml 46                                                      111       10 μg/ml 32                                                      112       10 μg/ml 43                                                      122       10 μM    73                                                      124       10 μM    79                                                      128       10 μM    73                                                      132       10 μM    74                                                      134       10 μM    66                                                      135       10 μM    45                                                      144       10 μM    60                                                      153       10 μM    74                                                      157       10 μM    72                                                      158       10 μM    65                                                      ______________________________________                                    

EXAMPLES Reference Example 1

A mixture of N-benzyloxycarbonyl-(L)-isoleucyl-(L)-tryptophan methylester (11.3 g), palladium-carbon (5%, 50% wet, 3.0 g) and THF (50 ml)was subjected to catalytic hydrogenation at room temperature andatomospheric pressure. After the catalyst was filtered off, the filtratewas concentrated under reduced pressure to yield an oily substance. Theoil was dissolved in N,N-dimethylformamide (50 ml), and1-naphthalenesulfonyl chloride (5.8 g) and 4-(N,N-dimethylamino)pyridine(DMAP) (3.2 g) were added to the ice-cooling mixture. After stirring at0° C. for 3 hours, the reaction mixture was concentrated under reducedpressure. The residue was suspended in ethyl acetate and the mixture wassuccessively washed with 10% aqueous citric acid solution, water,saturated aqueous sodium hydrogen carbonate and brine, and dried(MgSO₄). The organic solvent was evaporated off to yieldN-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-tryptophan methyl ester (9.8 g,77%) as crystals. Melting point: 172°-174° C.

Reference Example 2

To an ice-cooled mixture ofN-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-tryptophan methyl ester (6.9 g)and THF (40 ml)-methanol (20 ml) was added dropwise a solution of KOH(1.5 g) in water (10 ml). After stirring at 0° C. for 20 hours, thereaction mixture was acidified with 1N HCl (35 ml) with ice-cooling,diluted with water and extracted with ethyl acetate. The ethyl acetatelayer was washed with brine and dried (MgSO₄). The organic solvent wasevaporated off to yieldN-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-tryptophan (6.6 g, 98%) ascrystals. Melting point: 167°-168° C.

Reference Example 3

To a stirred solution of p-nitrobenzyl chloride (15 g) and diethylbenzylmalonate (22 g) in N,N-dimethylformamide (150 ml) was added NaH(60% in oil, 3.8 g). After stirring at room temperature for 2 days, thereaction mixture was concentrated under reduced pressure and the residuewas suspended in ethyl acetate. The ethyl acetate layer was washed withaqueous citric acid solution, water, saturated aqueous sodium hydrogencarbonate solution and brine, and dried (MgSO₄). The organic solvent wasevaporated off and the residual oil was purified by columnchromatography on silica gel. Elution with ethyl acetate-hexane (1:6,v/v) gave diethyl benzyl-4-nitrobenzylmalonate (24 g, 71%) as crystals.Melting point: 70°-71° C.

Reference Example 4

A mixture of diethyl benzyl-4-nitrobenzylmalonate (24 g), KOH (14 g) andwater (100 ml)-ethanol (150 ml) was stirred at 90°-100° C. for 7 hours.The reaction mixture was concentrated under reduced pressure and theresidue was acidified with 1N HCl and extracted with ethylacetate. Theethyl acetate layer was washed with brine, dried (MgSO₄) andconcentrated under reduced pressure. The residue was dissolved inpyridine (100 ml) and the solution was stirred at 90° C. for 16 hours.The organic solvent was evaporated off and the residue was acidifiedwith 1N HCl and extracted with ethyl acetate. The ethyl acetate layerwas washed with brine, dried (MgSO₄) and concentrated under reducedpressure. The residual oil was purified by column chromatography onsilica gel. Elution with ethyl acetate-hexane (1:3, v/v) gave2-benzyl-3-(p-nitrophenyl)propionic acid (10.5 g, 59%) as crystals.

Melting point: 104°-105° C.

Reference Example 5

2-Benzyl-3-(p-nitrophenyl)propionic acid was converted to N-2-benzyl-3-(p-nitrophenyl)propionyl!-(L)-tryptophanol by the methoddescribed for Example 1. Amorphous solid. α!_(D) : -12.5° (c 0.78,CHCl₃).

NMR (δ ppm in CDCl₃): 2.3-3.1 (7H,m), 3.2-3.4 (2H,m), 3.9-4.1 (1H,m),5.20 & 5.34 (1H, each d,J=7.2 Hz), 6.58 & 6.62 (1H, each d,J=2.0 Hz),7.0-7.4 (11H,m), 7.92 & 8.02 (2H, each d,J=8.2 Hz), 8.04 (1H, broad s)

Elemental analysis (for C₂₇ H₂₇ N₃ O₄.1/4H₂ O) Calculated: C, 70.19; H,6.00; N, 9.09 Found: C, 70.00; H, 6.25; N, 8.88

Reference Example 6

A mixture of diethyl 4-aminobenzylphosphonate (10 g) and diethylbenzylmalonate (24 g) was stirred at 160° C. for 24 hours. Aftercooling, the reaction mixture was purified by column chromatography onsilica gel. Elution with chloroform-methanol (100:1, v/v) gave ethyl2-(p-diethoxyphosphorylmethylphenylaminocarbonyl)-3-phenylpropionate(8.3 g, 45%) as crystals. Recrystallization from ethyl acetate-hexanegave colorless crystals having melting point of 115° to 116° C.

Reference Example 7

To an ice-cooled and stirred solution of ethyl2-(p-diethoxyphosphorylmethylphenylaminocarbonyl)-3-phenylpropionate(6.0 g) in THF (30 ml)-ethanol (10 ml) was added dropwise a solution ofKOH (0.9 g) in water (10 ml). After stirring at 4° C.-room temperaturefor 15 hours, the reaction mixture was acidified with 1N HCl, dilutedwith water and extracted with ethyl acetate. The ethyl acetate layer waswashed with brine and dried (MgSO₄). The organic solvent was evaporatedoff to yield2-(p-diethoxyphosphorylmethylphenylaminocarbonyl)-3-phenylpropionic acid(5.3 g, 94%) as crystals. Recrystallization from ethyl acetate-hexanegave pale yellow needles having melting point of 160° to 161° C.

Reference Example 8

To an ice-cooled and stirred solution ofN-(2-ethoxycarbonyl-3-phenylpropionyl)-(L)-tryptophanol (15 g) in THF(40 ml)-methanol (30 ml) was added dropwise a solution of KOH (2.5 g) inwater (10 ml). After stirring at 4° C.-room temperature for 20 hours,the reaction mixture was acidified with 1N HCl, diluted with water andextracted with ethyl acetate. The ethyl acetate layer was washed withbrine and dried (MgSO₄). The organic solvent was evaporated off to yieldN-(2-carboxy-3-phenylpropionyl)-(L)-tryptophanol (13.5 g, 97%) ascrystals. Recrystallization from ethyl acetate-hexane gave pale yellowcrystals having melting point of 130° to 131° C.

Example 1

A mixture of N-benzyloxycarbonyl-(L)-tryptophanol (0.974 g) in methanol(10 ml), palladium-carbon (10%, 0.195 g) was subjected to catalytichydrogenation at room temperature under 1 atmospheric pressure. Afterthe palladium-carbon was filtered off, the filtrate was concentratedunder reduced pressure to yield an oily substance. This oily substanceand N-benzyloxycarbonyl-(L)-phenylalanine (0.90 g) were dissolved intetrahydrofuran (THF) (20 ml), and 1-hydroxybenzotriazole (HOBt) (0.506g) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride(WSCD.HCl) (0.69 g) were added at 0° C. After stirring at roomtemperature for 21 hours, the reaction mixture was poured over ethylacetate. The ethyl acetate layer was washed by sequential additions of a10% aqueous citric acid solution, a saturated aqueous sodium hydrogencarbonate solution and saturated saline and then dried (MgSO₄). Afterthe solvent was distilled off, the oily residue was subjected to silicagel column chromatography and eluted with ethyl acetate-hexane (2:1) toyield N-benzyloxycarbonyl-(L)-phenylalanyl-(L)-tryptophanol (0.878 g,62%).

Melting point: 154°-156° C.

α!_(D) =-24.2° (c 0.24, DMSO)

Elemental analysis (for C₂₈ H₂₉ N₃ O₄.0.2H₂ O) Calculated: C, 70.78; H,6.24; N, 8.84 Found: C, 70.86; H, 6.25; N, 8.70

Examples 2 through 11

The same procedure as in Example 1 was followed to yield the compoundslisted in Table 3.

                                      TABLE 3                                     __________________________________________________________________________     ##STR20##                                                                                       Melting                                                                            Recrystallization                                                                     Optical Rotation                              Example No.                                                                         R            Point (°C.)                                                                 Solvent  α!.sub.D (c, solvent)                  __________________________________________________________________________    2     tBuOCOIIe    105-108                                                                            Ethyl acetate-                                                                        -31.5°                                                         hexane  (c 0.375, CHCl.sub.3)                         3     1-NapSO.sub.2Ile                                                                           150-151                                                                            CH.sub.2 Cl.sub.2ether                                                                -77.7°                                                                 (c 0.57, CHCl.sub.3)                          4     4-TolSO.sub.2Phe                                                                           159-160                                                                            Ethyl acetate-                                                                        -6.3°                                                          hexane  (c 0.485, DMSO)                               5     1-NapSO.sub.2Gly                                                                           Note.sup.1)                                                                        --      -9.2°                                                     --           (c 0.50, CHCl.sub.3)                          6     PhCH.sub.2 OCOIleIle                                                                       184-185                                                                            Tetrahydrofuran-                                                                      -40.0°                                                         hexane  (c 0.145, DMSO)                               7     PhCH.sub.2 OCOIle                                                                          184-185                                                                            Ethyl acetate-                                                                        -40.0° C.                                                      hexane  (c 0.50, DMSO)                                                   Note.sup.2)                                                                        --      -19.4°                                 8     tBuOCOIleIle --           (c 0.17, DMSO)                                9     1-NapSO.sub.2IleIle                                                                        170-172                                                                            Ethyl ether                                                                           -37.5°                                                                 (c 0.2, DMSO)                                 10    CH.sub.3 OCO(CH.sub.2).sub.2 CO                                                            213-214                                                                            Tetrahydrofuran-                                            IleIle            hexane                                                11    1-Ada(CH.sub.2).sub.2 OCO                                                                  Note.sup.3)                                                                        --                                                          IleIle       --                                                         __________________________________________________________________________     Ile: (L)isoleucine, Phe: (L)phenylalanine, Gly: glycine, tBu: tertbutyl,      1Nap: 1naphthyl, 4Tol: 4tolyl, Ph: phenyl, 1Ada: adamantan1-yl                Note .sup.1) Amorphous solid                                                  NMR(δ ppm in CDCl.sub.3): 2.69(2H, dd, J=4 & 6Hz), 3.35(2H, d,          J=6Hz), 3.25-3.49(3H, m), 4.06-4.14(1H, m), 6.32(1H, t, J=6Hz), 6.71(1H,      d, J=8.0Hz), 6.92(1H, d, J=2Hz), 7.04(1H, dt, J=1 & 7Hz), 7.13(1H, dt, J=     & 7Hz), 7.26(1H, d, J=8Hz), 7.39(1H, t, J=8Hz), 7.49(1H, d, J=10Hz),          7.50(2H, dd, J=7 & 9Hz), 7.86(1H, dd, J=3 & 7Hz), 7.96(1H, d, J=8Hz),         8.11(1H, dd, J=1 & 7Hz), 8.27(1H, d, J=2Hz), 8.50(1H, dd, J=3 & 6Hz)          Note .sup.2) Amorphous solid                                                  NMR(δ ppm in d.sub.6 -DMSO): 0.76-0.82(12H, m), 1.00-1.18(2H, m),       1.28-1.47(2H, m), 1.37(9H, s), 1.60-1.75(2H, m), 2.67-2.96(2H, m),            3.31-3.36(2H, m), 3.77-3.85(1H, m), 3.93-4.04(1H, m), 4.13-4.22(1H, m),       4.65(1H, t, J=5.2Hz), 6.87-7.09(4H, m), 7.32(1H, d, J=7.4Hz),                 7.59-7.78(3H, m), 10.75(1H, br s). SIMS m/z: 517(MH.sup.+).                   Note.sup.3) Amorphous solid                                                   NMR(δ ppm in d.sub.6 -DMSO): 0.74-0.83(12H, m), 0.98-1.16(2H, m),       1.28-1.90(21H, m), 2.68-2.95(2H, m), 3.25-3.42(2H, m), 3.83-4.21(5H, m),      4.65(1H, t, J=5.6Hz), 6.92-7.16(4H, m), 7.31(1H, d, J=7.4Hz), 7.62(1H, d,     J=7.0Hz), 7.69-7.75(2H, m), 10.74(1H, br s), SIMS m/z: 623(MH.sup.+).    

Example 12

The same procedure as in Example 1 was followed to yieldN-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-isoleucyl-(DL)-(1-naphthyl)alaninol, which was recrystallized fromethyl acetate.

Melting point: 198°-200° C.

Example 13

A mixture of N-benzyloxycarbonyl-(L)-isoleucyl-(L)-tryptophanol (2.14g), palladium-carbon (5%, 50% wet, 1.0 g) and methanol-THF (5:1, 30 ml)was subjected to catalytic hydrogenation at room temperature andatomospheric pressure. After the catalyst was filtered off, the filtratewas concentrated under reduced pressure to yield an oily substance. Theoil and valproic acid (0.71 g) were dissolved in N,N-dimethylformamide(20 ml), and 1-hydroxybenzotriazole (HOBt) (0.82 g) and a solution of1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride(WSCD•HCl)(1.13 g) in dichloromethane (20 ml) were added thereto at 0°C. After stirring at 0° C. for 1 hour and at room temperature for 15hours, the reaction mixture was concentrated under reduced pressure andthe residue was suspended in ethyl acetate (120 ml). The mixture wassuccessively washed with 10% aqueous citric acid solution, water,saturated aqueous sodium hydrogen carbonate and brine, and dried(MgSO₄). The organic solvent was evaporated off to yieldN-valproyl-(L)-isoleucyl-(L)-tryptophanol (1.78 g, 84.8%) as crystals.

Recrystallization from ethyl acetate-hexane gave colorless needles.

Melting point: 190°-191° C.

α!_(D) =-60.8° (c 0.50, CH₃ OH)

Elemental analysis (for C₂₅ H₃₉ N₃ O₃) Calculated: C, 69.90; H, 9.15; N,9.78 Found: C, 69.69; H, 9.14; N, 9.50

Example 14

A mixture of N-benzyloxycarbonyl-(L)-tryptophanol (1.0 g) in ethanolhydrogenation (20 ml)-dioxane (40 ml), palladium-carbon (5%, 0.5 g) wassubjected to catalytic hydrogenation at room temperature under 1atmospheric pressure. After the palladium-carbon was filtered off, thefiltrate was concentrated under reduced pressure to yield an oilysubstance. This oily substance was dissolved in N,N-dimethylformamide(10 ml), and 1-naphthalenesulfonyl chloride (0.77 g) was added and thentriethylamine (0.39 g) was added at 0° C. After overnight stirring atroom temperature, the reaction mixture was poured over water andextracted with ether. The ether layer was washed by sequential additionsof a 10% aqueous citric acid solution, a saturated aqueous sodiumhydrogen carbonate solution and saturated saline and then dried (MgSO₄).After the solvent was distilled off, the oily residue was subjected tosilica gel column chromatography and eluted with ethyl acetate-hexane(1:1) to yield a powder of N-(1-naphthylsulfonyl)-(L)-tryptophanol (0.8g, 68%).

Melting point: 85°-87° C.

α!_(D) =-104.9° (c 0.5, CHCl₃)

Example 15

A solution of N-benzyloxycarbonyl-(DL)-α-naphthylalanine (6.0 g) inethyl acetate (200 ml) was treated with a solution of diazomethane inether to yield N-benzyloxycarbonyl-(DL)-α-naphthylalanine methyl esteras an oily substance. This oily substance was dissolved in ethanol (60ml)-tetrahydrofuran (THF) (40 ml), and sodium borohydride (1.3 g) andlithium chloride (LiCl) (1.5 g) were added under an argon stream. Afterstirring at room temperature for 1 hour, the reaction mixture wasconcentrated under reduced pressure, and the residue poured over ethylacetate. The ethyl acetate layer was washed by sequential additions of asaturated aqueous sodium hydrogen carbonate solution and saturatedsaline and then dried (MgSO₄). The solvent was distilled off to yieldN-benzyloxycarbonyl-(DL)-α-naphthylalaninol (5.3 g, 91%) as a colorlesssolid.

¹ H-NMR (δ ppm in CDCl₃): 3.29 (1H,dd,J=8.2&12.8 Hz), 3.42(1H,dd,J=7.2&12.8 Hz), 3.5-3.8 (2H,m), 4.0-4.2 (1H,m), 5.11 (2H,s),7.3-7.9 (12H,m), 8.21 (1H,d,J=7.2 Hz)

Example 16

A mixture of N-benzyloxycarbonyl-(L)-isoleucyl-(L)-tryptophanol (55 g),palladium-carbon (5%, 50% wet, 30 g) and ethanol (50 ml)-THF (300 ml)was subjected to catalytic hydrogenation at room temperature andatomospheric pressure. After the catalyst was filtered off, the filtratewas concentrated under reduced pressure to yield an oily substance. Theoil was dissolved in N,N-dimethylformamide (300 ml), and1-naphthalenesulfonyl chloride (30 g) and 4-(N,N-dimethylamino)pyridine(DMAP) (17 g) were added to the ice-cooling mixture. After stirring at0° C. for 2 hours, the reaction mixture was concentrated under reducedpressure. The residue was suspended in ethyl acetate and the mixture wassuccessively washed with 10% aqueous citric acid solution, water,saturated aqueous sodium hydrogen carbonate and brine, and dried(MgSO₄). The organic solvent was evaporated off and the residual oil waspurified by column chromatography on silica gel. Elution with ethylacetate-hexane (3:2, v/v) gaveN-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-tryptophanol (51 g, 82%) ascrystals.

Example 17

To a solution, being ice cooled, ofN-tert-butoxycarbonyl-(L)-isoleucyl-(L)-tryptophanol (1.0 g) inchloroform (10 ml), trifluoroacetic acid (5%, 0.5 g) was added, followedby stirring at the same temperature for 4 hours. After the reactionmixture was concentrated under reduced pressure, ethyl acetate was addedto the residue. The ethyl acetate layer was washed with water and dried(MgSO₄), and the solvent was distilled off to yield(L)-isoleucyl-(L)-tryptophanol as an oily substance. This oily substancewas dissolved in chloroform (20 ml), and p-toluenesulfonyl chloride(0.52 g) was added and then triethylamine (1.4 ml) was added at 0° C.After stirring at room temperature for 2 days, the reaction mixture waspoured over water and extracted with chloroform. After the chloroformlayer was dried (MgSO₄), the solvent was distilled off, and the oilyresidue was recrystallized from ethyl acetate to yieldN-(p-toluenesulfonyl)-(L)-isoleucyl-(L)-tryptophanol (0.32 g, 28%).

Melting point: 217°-219° C.

α!_(D) =-32.7° (c 0.695, CH₃ OH)

Example 18

A mixture of N-benzyloxycarbonyl-(L)-isoleucyl-(L)-tryptophanol (0.7 g)in ethanol (30 ml)-tetrahydrofuran (20 ml), palladium-carbon (5%, 0.5 g)was subjected catalytic hydrogenation at room temperature under 1atmospheric pressure. After the palladium-carbon was filtered off, thefiltrate was concentrated under reduced pressure to yield an oilysubstance. This oily substance was dissolved in dichloromethane (15ml)-tetrahydrofuran (5 ml), and m-methylphenyl isocyanate (0.225 g) wasadded at 4° C. After stirring at room temperature for 1.5 hours, thereaction mixture was poured over chloroform-methanol. After theinsoluble substances were filtered off, the filtrate was concentratedunder reduced pressure, and the residual solid was recrystallized fromdichloromethane-methanol-hexane to yieldN-(3-methylphenylcarbamoyl)-(L)-isoleucyl-(L)-tryptophanol (0.43 g,61%).

Melting point: 185°-186° C.

Elemental analysis (for C₂₅ H₃₂ N₄ O₃) Calculated: C, 68.78; H, 7.39; N,12.83 Found: C, 68.35; H, 7.41; N, 12.91

Example 19

The same procedure as in Example 18 was followed to yieldN-benzylcarbamoyl-(L)-isoleucyl-(L)-tryptophanol.

Melting point: 132°-133° C.

α!_(D) =-42.9° (c 0.34, DMSO)

Example 20

The same procedure as in Example 18 was followed to yield N-(2-cyclohexylethyl)carbamoyl!-(L)-isoleucyl-(L)-tryptophanol.

Melting point: 182°-184° C.

α!_(D) =-27.7° (c 0.37, DMSO)

Example 21

The same procedure as in Example 18 was followed to yieldN-isopropylcarbamoyl-(L)-isoleucyl-(L)-tryptophanol.

Melting point: 211°-213° C.

Example 22

The same procedure as in Example 18 was followed to yield N-(2-trifluoromethylphenyl)carbamoyl!-(L)-isoleucyl-(L)-tryptophanol.

Melting point: 232°-234° C.

Examples 23 through 53

The same procedure as in Examples 1, 16 and 18 was followed to yield thecompounds listed in Table 4.

                                      TABLE 4                                     __________________________________________________________________________     ##STR21##                                                                                                         Procedure                                Example         Melting                                                                            Recrystallization                                                                     Optical Rotation                                                                      followed                                 No.  R          Point (°C.)                                                                 Solvent  α!.sub.D (c, solvent)                                                          (Example No.)                            __________________________________________________________________________    23   PhCH.sub.2 OCOGly                                                                        87-88                                                                              Ethyl acetate-                                                                        -15.0°                                                                         1                                                             ether   (0.50, CHCl.sub.3)                               24   tBuOCOPhe  150-151                                                                            Ethyl acetate-                                                                        -20.2°                                                                         1                                                             hexane  (0.96, CHCl.sub.3)                               25   1-NapSO.sub.2Phe                                                                         --.sup.1)    -113.3°                                                                        16                                                                    (0.86, CHCl.sub.3)                               26   (PhCH.sub.2).sub.2 CHCO                                                                  120-121                                                                            Ethyl acetate-                                                                        -13.9°                                                                         1                                                             hexane  (0.62, CHCl.sub.3)                               27   PhCH.sub.2 CH.sub.2 CO                                                                   134-135                                                                            Ethyl acetate-                                                                        -14.5°                                                                         1                                                             hexane  (0.54, CHCl.sub.3)                               28   1-NapSO.sub.2Ala                                                                         --.sup.2)    -77.5°                                                                         16                                                                    (0.50, CHCl.sub.3)                               29   (C.sub.3 H.sub.7).sub.2 CHCOAla                                                          144-145                                                                            Ethyl acetate-                                                                        -64.7°                                                                         13                                                            hexane  (0.50, CH.sub.3 OH)                              30   PhCH.sub.2 OCOTrp                                                                        105-106                                                                            Ethyl acetate-                                                                        -43.4°                                                                         1                                                             ether   (1.05, DMSO)                                     31   tBuOCOTrp  120-122                                                                            Ethyl acetate-                                                                        -39.7°                                                                         1                                                             ether   (0.62, DMSO)                                     32   PhCOPhe    165-167                                                                            DMF-H.sub.2 O                                                                         -46.3°                                                                         1                                                                     (0.745, DMSO)                                    33   (PhS)(C.sub.3 H.sub.7)CHCO                                                               141-142                                                                            Ethyl acetate                                                                         +66.6°                                                                         1                                                                     (0.55, CHCl.sub.3)                               34   PhCH.sub.2 NHCSIle                                                                       --.sup.3)                                                                          Ethyl acetate-                                                                        -40.4°                                                                         18                                                            ether   (0.255, DMSO)                                    35   1-NapNHCOIle                                                                             217-218                                                                            Ethyl acetate-                                                                        -5.6°                                                                          18                                                            methanol                                                                              (0.325, DMSO)                                    36   PhCH.sub.2 OCOVal                                                                        163-164                                                                            Ethyl acetate-                                                                        -43.3°                                                                         1                                                             hexane  (0.50, CH.sub.3 OH)                              37   1-NapSO.sub.2Val                                                                         --.sup.4)    -28.8°                                                                         16                                                                    (0.50, CH.sub.3 OH)                              38   PhCOVal    173-174                                                                            Ethyl acetate-                                                                        -35.8°                                                                         1                                                             hexane  (0.50, CH.sub.3 OH)                              39   (C.sub.3 H.sub.7).sub.2 CHCOVal                                                          187-188                                                                            Ethyl acetate-                                                                        -63.8°                                                                         13                                                            hexane  (0.50, CH.sub.3 OH)                              40   (2-benzimidazolyl-S)                                                                     165-167                                                                            Ethyl acetate-                                                                        -52.1°                                                                         1                                             (C.sub.3 H.sub.7)CHCO                                                                         hexane  (0.53, CH.sub.3 OH)                              41   PhNHCSIle  --.sup.5)                                                                          --      -26.9°                                                                         18                                                                    (0.295, CHCl.sub.3)                              42   1-NapNHCSIle                                                                             --.sup.6)                                                                          --      -11.7°                                                                         16                                                                    (0.43, CHCl.sub.3)                               43   PhCOGly    149-150                                                                            Ethyl acetate-                                                                        -16.3°                                                                         1                                                             hexaner (0.50, CH.sub.3 OH)                              44   PhCH.sub.2 OCOAla                                                                        158-159                                                                            Ethyl acetate-                                                                        -40.1°                                                                         1                                                             hexane  (0.50, CH.sub.3 OH)                              45   PhCH.sub.2 OCOLeu                                                                        103-104                                                                            Ethyl acetate-                                                                        -46.1°                                                                         1                                                             hexane  (0.50, CH.sub.3 OH)                              46   1-NapSO.sub.2Leu                                                                         --.sup.7)                                                                          --      -100.7°                                                                        16                                                                    (0.50, CHCl.sub.3)                               47   PhCOLeu    200-201                                                                            Ethyl acetate                                                                         -39.5°                                                                         1                                                                     (0.50, CH.sub.3 OH)                              48   (C.sub.3 H.sub.7).sub.2 CHCOLeu                                                          149-150                                                                            Ethyl acetate-                                                                        -64.8°                                                                         13                                                            hexane  (0.50, CH.sub.3 OH)                              49   (C.sub.3 H.sub.7).sub.2 CHCOGly                                                          177-178                                                                            Ethyl acetate-                                                                        -13.2°                                                                         13                                                            hexane  (0.50, CH.sub.3 OH)                              50   PhCOIle    142-143                                                                            Ethyl acetate-                                                                        -27.2°                                                                         1                                                             hexane  (0.26, CHCl.sub.3)                               51   Ph(CH.sub.2).sub.3 CO                                                                     99-100                                                                            Ethyl acetate-                                                                        -15.5°                                                                         1                                                             hexane  (0.435, CHCl.sub.3)                              52   (C.sub.3 H.sub.7).sub.2 CHCOPhe                                                          191-192                                                                            Ethyl acetate-                                                                        -34.3°                                                                         13                                                            hexane  (0.50, CH.sub.3 OH)                              53   (C.sub.3 H.sub.7).sub.2 CHCO                                                             153-154                                                                            CHCl.sub.3 -ethanol-                                                                  -19.8°                                                                         1                                                             isopropyl ether                                                                       (0.50, CHCl.sub.3)                               __________________________________________________________________________

Examples 54 through 68

The same procedure as in Example 1 and 16 was followed to yield thecompounds listed in Table 5.

                                      TABLE 5                                     __________________________________________________________________________     ##STR22##                                                                                                                      Procedure                                                                     followed                    Example                       Melting                                                                            Recrystalliza-                                                                       Optical Rotation                                                                      (Example                    No   R.sup.4 R.sup.1          Point (°C.)                                                                 tion Solvent                                                                          α!.sub.D (c,                                                                   No.)ent)                    __________________________________________________________________________    54   tBuOCO                                                                                 ##STR23##       132-133                                                                            CH.sub.2 Cl.sub.2  Ethyl acetate-                                             hexane -25.7° (0.34,                                                                  1MSO)                       55   PhCH.sub.2 OCO                                                                        CH.sub.3         156-157                                                                            methanol                                                                             +2.3°                                                                          1                                                              CH.sub.2 Cl.sub.2                                                                    (0.375,                                                                hexane DMSO)                               56   PhCH.sub.2 OCO                                                                        CH.sub.2 Ph      164-165                                                                            methanol-                                                                            -38.0°                                                                         1                                                              ethyl acetate                                                                        (0.27, DMSO)                        57   1-NapSO.sub.2                                                                         CH.sub.3         178-179                                                                            Ethyl  +54.3°                                                                         16                                                             acetate-                                                                             (0.38, DMSO)                                                           hexane                                     58   1-NapSO.sub.2                                                                         CH.sub.2 Ph      169-170                                                                            Ethyl  -108.3°                                                                        16                                                             acetate-                                                                             (0.65, CHCl.sub.3)                                                     hexane                                     59   PhCH.sub.2 OCO                                                                         ##STR24##       117-118                                                                            Ethyl acetate- hexane                                                                -22.6° (0.295. CHCl.sub.3                                              )       1                           60   PhCH.sub.2 OCO                                                                         ##STR25##       188-189                                                                            Ethyl acetate- hexane                                                                -34.0° (0.355, DMSO)                                                           1                           61   PhCH.sub.2 OCO                                                                         ##STR26##       174-175                                                                            Ethyl acetate- hexane                                                                -34.0° (0.38,                                                                  1MSO)                       62   1-NapSO.sub.2                                                                          ##STR27##       204-205                                                                            Ethyl acetate- hexane                                                                -9.3° (0.36,                                                                   16SO)                       63   1-NapSO.sub.2                                                                          ##STR28##       130-131                                                                            Ethyl acetate- hexane                                                                -92.3° (0.34.                                                          CHCl.sub.3)                                                                           16                          64   PhCH.sub.2 OCO                                                                        CH(CH.sub.3).sub.2                                                                             149-150                                                                            Ethyl acetate                                                                        -36.7°                                                                         1                                                                     (0.37. CHCl.sub.3)                  65   PhCH.sub.2 OCO                                                                        CH.sub.2 CH(CH.sub.3).sub.2                                                                    151-153                                                                            Ethyl  -34.1°                                                                         1                                                              acetate-                                                                             (0.36. CHCl.sub.3)                                                     hexane                                     66   1-NapSO.sub.2                                                                         CH(CH.sub.3).sub.2                                                                             159-160                                                                            Ethyl acetate                                                                        +8.0°                                                                          16                                                                    (0.26. CHCl.sub.3)                  67   1-NapSO.sub.2                                                                         CH.sub.2 CH(CH.sub.3).sub.2                                                                    88-89                                                                              Ethyl- +28.5°                                                                         16                                                             acetate-                                                                             (0.265,                                                                hexane DMSO)                               68   PhCH.sub.2 OCO                                                                        H                160-161                                                                            Ethyl  -4.9°                                                                          1                                                              acetate-                                                                             (0.50. CHCl.sub.3)                                                     hexane                                     __________________________________________________________________________     DMSO: dimethyl sulfoxide, Ph: phenyl, 1Nap: 1naphthyl, tBu: tert. butyl  

Examples 69 through 73

The same procedure as in Example 1 was followed to yield the compoundslisted in Table 6.

                                      TABLE 6                                     __________________________________________________________________________     ##STR29##                                                                    Example             Melting                                                                            Recrystalliza-                                                                       Optical Rotation                              No   R        R.sup.1                                                                             Point (°C.)                                                                 tion Solvent                                                                          α!.sub.D (c, solvent)                  __________________________________________________________________________    69   (PhCH.sub.2).sub.2 CHCO                                                                CH.sub.2 Ph                                                                         115-116                                                                            CH.sub.2 Cl.sub.2 -                                                                  -18.3°                                                          hexane (0.56, CHCl.sub.3)                            70   PhCH.sub.2 OCOLeu-                                                                     H     112-113                                                                            Ethyl acetate-                                                                       -17.0°                                      Leu                 hexane (0.305, DMSO)                                 71   (PhCH.sub.2).sub.2 CHCO                                                                CH.sub.2 CH.sub.3                                                                   161-162                                                                            Ethyl acetate-                                                                       -34.6°                                                          methanol-                                                                            (0.54, CHCl.sub.3)                                                     hexane                                               72   (PhCH.sub.2).sub.2 CHCO                                                                CH(CH.sub.3).sub.2                                                                  148-149                                                                            Ethyl aceate-                                                                        -31.5°                                                          hexane (0.50, CHCl.sub.3)                            73   (PhCH.sub.2).sub.2 CHCO                                                                CH.sub.3                                                                            144-145                                                                            CHCl.sub.2 -                                                                         -17.9°                                                          isopropyl                                                                            (0.50, CHCl.sub.3)                                                     ether-hexane                                         __________________________________________________________________________     Leu: (L)leucine, Ph: phenyl                                              

Example 74

The same procedure as in Example 1 was followed to yieldN-benzyloxycarbonyl-(L)-isoleucyl-(D)-tryptophanol.

m.p. 198°-199° C. (recrystallized from ethyl acetate-hexane).

α!_(D) =+31.8° (c 0.945, DMSO)

Example 75

The same procedure as in Example 16 was followed to yieldN-(1-naphthylsulfonyl)-(L)-isoleucyl-(D)-tryptophanol as an amorphoussolid.

α!_(D) =-16.0° (c0.34, CHCl₃)

NMR(δ ppm in CDCl₃): 0.4-0.9 (7H,m), 1.1-1.3 (1H,m), 1.5-1.7 (1H,m),2.6-2.8 (1H,m), 2.74 (2H,d,J=7.0 Hz), 3.2-3.4 (2H,m), 3.45(1H,dd,J=6.0&8.2 Hz), 3.9-4.2 (1H,m), 5.7-5.9 (1H,m), 6.1-6.3 (1H,m),7.00 (1H,d,J=1.6 Hz), 7.0-7.7 (7H,m), 7.90 (1H,d,J=8.0 Hz), 7.99(1H,d,J=8.4 Hz), 8.20 (2H,d,J=7.2 Hz), 8.67 (1H,d,J=8.2 Hz)

Examples 76 through 97

The same procedure as in Examples 1 and 13 was followed to yield thecompounds listed in Tables 7 and 8.

                                      TABLE 7                                     __________________________________________________________________________     ##STR30##                                                                                                            Procedure                                                                     followed                              Example             Melting                                                                            Recrystalliz-                                                                        Optical Rotation                                                                      (Example                              No   R.sup.4   R.sup.1                                                                            Point (°C.)                                                                 ation Solvent                                                                         α!.sub.D (c, solvent)                                                          No.)                                  __________________________________________________________________________    76   (C.sub.3 H.sub.7).sub.2 CHCO                                                            PhCH.sub.2                                                                         133-134                                                                            CHCl.sub.2 -                                                                         -25.4°                                                                         1                                                              ether- (0.5, CHCl.sub.3)                                                      isopropyl                                                                     ether                                                77   Ph(CH.sub.2).sub.3 CO                                                                   PhCH.sub.2                                                                         113-114                                                                            AcOEt-ether-                                                                         -22.8°                                                                         1                                                              hexane (0.5, CHCl.sub.3)                             78   PhCH.sub.2 OCO                                                                          H    126-127                                                                            AcOEt- +11.6°.sup.1)                                                                  1                                          Leu                 hexane (0.41, DMSO)                                  79   1-NapSO.sub.2Leu                                                                        H    215-216                                                                            AcOEt  -15.4°                                                                         1                                          Trp                        (0.24, DMSO)                                  __________________________________________________________________________     Leu: (L)leucine, Trp: (L)tryptophan, Ph: phenyl, 1Nap: 1naphthyl, AcOEt:      ethyl acetate                                                                 .sup.1)  α!.sub.Hg                                                 

                                      TABLE 8                                     __________________________________________________________________________     ##STR31##                                                                                                           Procedure                              Example           Melting                                                                            Recrystalliza-                                                                       Optical Rotation                                                                       followed                               No.  R            Point (°C.)                                                                 tion Solvent                                                                          α!.sub.D (c, solvent)                                                           (Example No.)                          __________________________________________________________________________    80   (CH.sub.3).sub.2 CHCH.sub.2 CH.sub.2 CO                                                    114-115                                                                            AcOEt-hexane                                                                         -19.0°                                                                          1                                                                    (0.5, CH.sub.3 OH)                              81   cyclohexyl-CO                                                                              164-165                                                                            AcOEt-hexane                                                                         -20.8°                                                                          1                                                                    (0.5, CH.sub.3 OH)                              82   PhCO         129-130                                                                            AcOEt-hexane                                                                         -74.4°                                                                          1                                                                    (0.5, CH.sub.3 OH)                              83   Ph(C.sub.2 H.sub.5)CHCO                                                                    103-104                                                                            AcOEt-hexane                                                                         -22.4°                                                                          1                                                                    (0.645, CHCl.sub.3)                             84   (PhCH.sub.2) (4-CH.sub.3                                                                   --.sup.1)   -16.0°                                                                          1                                           C.sub.6 H.sub.4)CH.sub.2 !CHCO                                                                         (0.53, CHCl.sub.3)                              85   PhCH.sub.2 CH.sub.2COVal                                                                   197-198                                                                            AcOEt-hexane                                                                         -60.7° C.                                                                       13                                                                   (0.50, CH.sub.3 OH)                             86   (PhCH.sub.2).sub.2 CHCOVal                                                                 157-158                                                                            AcOEt-hexane                                                                         -48.3    13                                                                   (0.50, CH.sub.3 OH)                             87   (PhCH.sub.2) (2-CH.sub.3 O                                                                  98-100     -17.5°                                                                          1                                           C.sub.6 H.sub.4)CH.sub.2 !CHCO                                                                         (0.53, CHCl.sub.3)                              88   (PhCH.sub.2) (4-CH.sub.3 O                                                                 --.sup.2)   -24.8°                                                                          1                                           C.sub.6 H.sub.4)CH.sub.2 !CHCO                                                                         (0.59, CHCl.sub.3)                              89    (4-PhCONH   173-174                                                                            AcOEt-hexane                                                                         -65.5°                                                                          --.sup.6)                                   C.sub.6 H.sub.4)CH.sub.2 !(PhCH.sub.2)CH                                                               (0.535, CHCl.sub.3)                                  CO                                                                       90    (4-CH.sub.3 CONH                                                                          114-115                                                                            AxOEt-hexane                                                                         -18.0°                                                                          --.sup.7)                                   C.sub.6 H.sub.4)CH.sub.2!(PhCH.sub.2)CH                                                                (0.475, CHCl.sub.3)                                  CO                                                                       91    4-(4-Tol-SO.sub.2 NH)                                                                     150-151                                                                            AcOEt-hexane                                                                         -16.1°                                                                          --.sup.8)                                   C.sub.6 H.sub.4 CH.sub.2 !(PhCH.sub.2)CH                                                               (0.815, DMSO)                                        CO                                                                       92     4-(C.sub.2 H.sub.5 O).sub.2 P(O)CH.sub.2 !                                               --.sup.3)   -37.1°                                                                          1                                           C.sub.6 H.sub.4 NHCO!(PhCH.sub.2)CH                                                                    (0.52, CHCl.sub.3)                                   CO                                                                       93   (C.sub.2 H.sub.5 OOC)(PhCH.sub.2)CH                                                        --.sup.4)            1                                           CO                                                                       94    (PhCH.sub.2).sub.2 NCO!                                                                   --.sup.5)   -21.8°                                                                          --.sup.9)                                   (PhCH.sub.2)CHCO         (0.405, CHCl.sub.3)                             95   (PhCH.sub.2 NHCO)                                                                          187-188                                                                            AcOEt-hexane                                                                         -40.8°                                                                          .sup. --.sup.10)                            (PhCH.sub.2)CHCO         (0.83, DMSO)                                    96   Ph.sub.2 CHCO                                                                              207-209                                                                            AcOEt-hexane                                                                         -24.8°                                                                          1                                                                    (0.345, DMSO)                                   97   (4-oxo-4H-1-benzopyran-                                                                    164-165                                                                            ethanol-hexane                                                                       -54.8°                                                                          13                                          2-yl)-COIle              (0.53, CH.sub.3 OH)                             __________________________________________________________________________     Leu: (L)leucine, Val: (L)valine, Ph: phenyl, 4Tol: 4tolyl, AcOEt: ethyl       acetate                                                                       Note .sup.1) Amorphous solid                                                  NMR(δ ppm in CDCl.sub.3): 2.29 & 2.31(3H, each s), 2.34-2.52(1H, m)     2.60-3.08(6H, m), 3.18-3.42(2H, m), 3.93-4.11(1H, m), 5.10-5.20(1H, m),       6.42 & 6.50(1H, each d, J=2.2Hz), 7.00-7.40(13H, m), 7.89(1H, broad).         Note .sup.2) Amorphous solid                                                  NMR(δ ppm in CDCl.sub.3): 2.32-2.50(1H, m), 2.60-3.07(4H, m),           3.20-3.43(2H, m), 3.75 & 3.78(3H, each s), 3.92-4.15(1H, m), 5.04-5.20(1H     m), 6.31 & 6.43(1H, each d, J=2.3Hz), 6.79(2H, d, J=8.5Hz), 7.02-7.46(9H,     m), 7.87-8.00(1H, broad).                                                     Note .sup.3) Amorphous solid                                                  NMR(δ ppm in CDCl.sub.3): 1.22(3H, t, J=6.0Hz), 1.23(3H, t,             J=6.0Hz), 2.70-3.60(10H, m), 3.90-4.10(4H, m), 4.1-4.30(1H, m), 6.70 &        6.83(1H, each d, J=2.2Hz), 6.82 & 6.88(1H, each d, J=8.0Hz), 7.0-7.4(12H,     m), 7.52 & 7.58(1H, each d, J=7.4Hz), 8.37 & 8.46(1H, each broad s), 9.29     & 9.31(1H, each broad s).                                                     Note .sup.4) Oil                                                              NMR(δ ppm in CDCl.sub.3): 1.10 & 1.12(3H, each t, J=7.0Hz),             2.40-2.60(1H, m), 2.91-3.22(5H, m), 3.41-3.70(2H, m), 3.98-4.30(3H, m),       6.50-6.65(1H, m), 6.89 & 6.98(1H, each d, J=2.2Hz), 7.07-7.37(8H, m), 7.5     & 7.65(1H, each d, J=7.8Hz), 8.15(1H, broad).                                 Note .sup.5) Amorphous solid                                                  NMR(δ ppm in CDCl.sub.3): 2.6-3.4(5H, m), 3.5-3.9(3H, m),               4.0-4.5(4H, m), 6.65(1H, d, J=6.8Hz), 6.71 & 6.75(1H, each d, J=2.8Hz),       6.9-7.4(18H, m), 7.68(1H, d, J=7.0Hz), 8.07(1H, broad s).                     Note .sup.6) Synthesized by catalytic reduction of                            N 2-benzyl-3-(p-nitrophenyl)propionyl!-(L)-tryptophanol (Reference Exampl     5) followed by reaction with benzoyl chloride.                                Note .sup.7) Synthesized by catalytic reduction of                            N 2-benzyl-3-(p-nitrophenyl)propionyl!-(L)-tryptophanol (Reference Exampl     5) followed by reaction with acetyl chloride.                                 Note .sup.8) Synthesized by catalytic reduction of                            N 2-benzyl-3-(p-nitrophenyl)propionyl!-(L)-tryptophanol (Reference Exampl     5) followed by reaction with tosyl chloride.                                  Note .sup.9) Synthesized by reaction of                                       N(2-carboxy-3-phenylpropionyl)-(L)-tryptophanol (Reference Example 8) wit     dibenzylamine using the method described for Example 1.                       Note .sup.10 Synthesized by reaction of                                       N(2-carboxy-3-phenylpropionyl)-(L)-tryptophanol (Reference Example 8) wit     benzylamine using the method described for Example 1.                    

Example 98

To a solution of N-benzyloxycarbonyl-(L)-phenylalanyl-(L)-tryptophanol(0.60 g) and triethylamine (0.53 ml) in dimethyl sulfoxide (DMSO) (7ml), a solution of pyridine-sulfur trioxide complex (pyridine.SO₃) inDMSO (7 ml) was added drop by drop. After stirring at room temperaturefor 1 hour, the reaction mixture was poured over ice water and extractedwith ethyl ether (60 ml×3). The ethyl ether layer was washed bysequential additions of a 10% aqueous citric acid solution, a saturatedaqueous sodium hydrogen carbonate solution and saturated saline and thendried (MgSO₄). After the solvent was distilled off, the residue wassolidified from THF-hexane-ethyl ether to yieldN-benzyloxycarbonyl-(L)-phenylalanyl-(L)-tryptophanal (0.44 g, 74%) as acolorless powder.

Melting point: 74°-77° C.

α!_(D) =+18.0° (c 0.05, CHCl₃, 31° C.)

Examples 99 through 117

The same procedure as in Example 98 was followed to yield the compoundslisted in Table 9.

                                      TABLE 9                                     __________________________________________________________________________     ##STR32##                                                                    Example               Melting                                                                              Recrystallization                                                                     Optical Rotation                         No.  R                Point (°C.)                                                                   Solvent  α!.sub.D (c,                      __________________________________________________________________________                                         solvent)                                  99  3-TolNHCOIle     202-204                                                                              Methanol-                                                                             -20.8°                                                  (decomposed)                                                                         dichloromethane-                                                                      (c 0.32, DMSO)                                                        hexane                                           100  1-NapSO.sub.2    160-161                                                                              Ethyl ether                                                                           -84.6°                                                                 (c 0.5, CHCl.sub.3)                      101  4-TolSO.sub.2Ile 199-201                                                                              --      -32.7°                                                                 (c 0.51, CH.sub.3 OH)                    102  tBuOCOIIe        114-115                                                                              Isopropyl ether                                                                       +22.3°                                                                 (c 0.775, CHCl.sub.3)                    103  1-NapSO.sub.2Ile 145-146                                                                              Ethyl acetate-                                                                        -54.4°                                                         hexane  (c 0.50, CHCl.sub.3)                     104  PhCH.sub.2 OCO   105-106                                                                              Ethyl acetate-                                                                        +49.0°                                                         isopropyl ether                                                                       (c 0.5, CHCl.sub.3)                      105  4-TolSO.sub.2Phe 150-151                                                                              Ethyl acetate-                                                                        +15.4°                                                         ethyl ether                                                                           (c 0.41, DMSO)                           106  1-NapSO.sub.2Gly 135-136                                                                              --      -54.8°                                                                 (c 0.50, CHCl.sub.3)                     107  PhCH.sub.2 OCOIle                                                                              137-140                                                                              Ethyl acetate-                                                                        +28,5°                                                         hexane  (c 0.4, MeOH)                            108  PhCh.sub.2 OCOIleIle                                                                           Note .sup.1)                                                                         --      +12.5°                                                  --             (c 0.12, CHCl.sub.3)                     109  tBuOCOIleIle     178-180                                                                              Tetrahydrofuran-                                                                      -36.5°                                                         dichloromethane-                                                                      (c 0.115, DMSO)                                                       hexane                                           110  1-NapSO.sub.2IleIle                                                                            159-160                                                                              Tetrahydrofuran-                                                                      -100.0°                                                        ethyl ether-                                                                          (c 0.125, CHCl.sub.3)                                                 hexane                                           111  CH.sub.3 OCO(CH.sub.2).sub.2                                                                   Note .sup.2)                                                                         --      --                                            COIIeIle         --                                                      112  1-Ada(CH.sub.2).sub.2 OCOIleIle                                                                Note .sup.3)                                                                         --      --                                                             --                                                      113  (C.sub.3 H.sub.7).sub.2 CHCO                                                                   135-136                                                                              Dichloromethane-                                                                      -86.8°                                                         ethyl ether                                                                           (c 0.5, CHCl.sub.3)                      114  PhCH.sub.2 NHCOIle                                                                             183-185                                                                              Chloroform-ethyl                                                                      -16.9°                                                         acetate (c 0.4, DMSO)                            115                                                                                 ##STR33##       168-169                                                                              Dichloromethane- ethyl acetate- hexane                                                -21.9° (c 0.325, DMSO)            116  (CH.sub.3).sub.2 CHNHCOIle                                                                     201-204                                                                              Methanol-ethyl                                                                        -15.9°                                                  (decomp.)                                                                            acetate (c 0.57, DMSO)                           117                                                                                 ##STR34##       185-186 (decomp.)                                                                    Methanol-ethyl acetate                                                                -18.7° (c 0.50,                   __________________________________________________________________________                                         DMSO)                                     Ile: (L)isoleucine, Phe: (L)phenylalanine, Gly: glycine, tBu: tertbutyl,      1Nap: 1naphthyl, 3Tol: 3tolyl, 4Tol: 4tolyl, Ph: phenyl, 1Ada:                adamantan1-yl                                                                 Note .sup.1) Amorphous solid                                                  NMR(δ ppm in CDCl.sub.3): 0.84-0.90(12H, m), 0.98-1.17(2H, m),          1.36-1.51(2H, m), 1.81-1.94(2H, m), 3.27-3.33(2H, m), 4.00(1H, dd, J=6.8      8.6Hz), 4.30(1H, dd, J=6.8 & 8.6Hz), 4.80(1H, dd, J=6.6 & 13.2Hz),            5.10(2H, s), 5.28(1H, d, J=7.6Hz), 6.48(1H, d, J=8.6Hz), 6.62(1H, d,          J=6.6Hz), 7.03-7.40, 7.55-7.60(10H, m), 8.25(1H, br s), 9.63(1H, s). SIMS     m/z: 549(MH.sup.+).                                                           Note .sup.2) Amorphous solid                                                  NMR(δ ppm in d.sub.6 -DMSO): 0.75-0.81(12H, m), 0.98-1.13(2H, m),       1.33-1.47(2H, m), 1.66-1.75(2H, m), 2.40-2.51(4H, m), 2.93-3.25(2H, m),       3.56(3H, s), 4.16-4.26(2H, m), 4.41(1H, dd, J=7.0 & 13.0Hz), 6.94-7.17(3H     m), 7.34(1H, d, J=8.0Hz), 7.52(1H, d, J=7.6Hz), 7.79(1H, d, J=8.6Hz),         7.96(1H, d, J=8.8Hz), 8.42(1H, d, J=6.4Hz), 9.47(1H, s), 10.86(1H, br s).     SIMS m/z: 529(MH.sup.+).                                                      Note .sup.3) Amorphous solid                                                  NMR(δ ppm in CDCl.sub.3): 0.85-0.91(12H, m), 1.02-1.19(2H, m),          1.36-1.96(21H, m), 3.20-3.41(2H, m), 3.93-4.02(1H, m), 4.09-4.16(2H, m),      4.32(1H, dd, J=6.8 & 8.4Hz), 4.82(1H, dd, J=7.0 & 13.4Hz), 5.12(1H, d,        J=8.2Hz), 6.48(1H, d, J=8.6Hz), 6.63(1H, d, J=7.0Hz), 7.03-7.25(3H, m),       7.37(1H, d, J=7.4Hz), 7.59(1H, d, J=7.2Hz), 8.28(1H, br s), 9.63(1H, s).      SIMS m/z: 621(MH.sup.+).                                                 

Example 118

The same procedure as in Example 98 was followed to yieldN-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-isoleucyl-(DL)-(1-naphthyl)alaninal,which was recrystallized from ethyl acetate-tetrahydrofuran-hexane.

Melting point: 169°-174° C.

NMR (δ ppm in CD₃ OD): 0.2-1.7 (8H, m), 3.0-3.2 (1H, m), 3.45 (1H, dd,J=7.2 & 18.0 Hz), 3.61 (1H, dd, J=4.0 & 14.2 Hz), 3.87 (1H, dd, J=7.2 &24.6 Hz), 4.2-4.4 (1H, m), 7.3-8.3 (13H, m), 8.74 (1H, t, J=8.6 Hz)

Example 119 through 149

The same procedure as in Example 98 was followed to yield the compoundslisted in Table 10.

                                      TABLE 10                                    __________________________________________________________________________     ##STR35##                                                                    Example           Melting                                                                             Recrystallization                                                                      Optical Rotation                             No.   R           Point (°C.)                                                                  Solvent   α!.sub.D (c, solvent)                 __________________________________________________________________________    119   PhCH.sub.2 OCOGly                                                                         131-132                                                                             ether-hexane                                                                           -16.1°                                                                 (0.50, CH.sub.3 OH)                          120   tBuOCOPhe    85-86                                                                              Ethyl acetate-                                                                         +17.4°                                                        hexane   (0.71, CHCl.sub.3)                           121   1-NapSO.sub.2Phe                                                                           85-86                                                                              Ethyl acetate-                                                                         -71.5°                                                  (dec.)                                                                              isopropyl ether                                                                        (0.745, CHCl.sub.3)                          122   (PhCH.sub.2).sub.2 CHCO                                                                   142-144                                                                             Ethyl acetate-                                                                         +14.1°                                                        isoprpyl ether                                                                         (0.57, CHCl.sub.3)                           123   PhCH.sub.2 CH.sub.2 CO                                                                    124-125                                                                             CH.sub.2 Cl.sub.2 -ether                                                               +60.0°                                                                 (0.58, CHCl.sub.3)                           124   1-NapSO.sub.2Ala                                                                          119-120                                                                             ether    +26.7°                                                  (dec.)         (0.50, CH.sub.3 OH)                          125   (C.sub.3 H.sub.7).sub.2 CHCOAla                                                           141-142                                                                             ether    -52.6°                                                                 (0.715, CH.sub.3 OH)                         126   PhCH.sub.2 OCOTrp                                                                          86-88                                                                              Ethyl acetate-                                                                         -7.6                                                                 isoprpyl ether                                                                         (0.715, CHCl.sub.3)                          127   tBuOCOTrp    95-97                                                                              ether-hexane                                                                           -23.0°                                                                 (0.68, DMSO)                                 128   PhCOPhe     113-115                                                                             DMFH.sub.2 O                                                                           -55.9°                                                  (dec.)         (0.78, DMSO)                                 129   (PhS)(C.sub.3 H.sub.7)CHCO                                                                111-112                                                                             CH.sub.2 Cl.sub.2 -ether                                                               +106.6°                                                                (0.52, CHCl.sub.3))                          130   PhCH.sub.2 NHCSIle                                                                        130-131                                                                             Ethyl acetate-                                                                         -12.9°                                                        isopropyl ether                                                                        (0.34, DMSO)                                 131   1-NapNHCOIle                                                                              192-193                                                                             Ethyl acetate-                                                                         +4.4°                                                   (dec.)                                                                              hexane   (0.395, DMSO)                                132   PhCH.sub.2 OCOVal                                                                          98-99                                                                              ether-hexane                                                                           -34.4°                                                                 (0.50, CH.sub.3 OH)                          133   1-NapSO.sub.2Val                                                                          117-118                                                                             ether-hexane                                                                           -17.2°                                                                 (0.50, CH.sub.3 OH)                          134   PhCOVal     120-121                                                                             ether-hexane                                                                           -26.9°                                                                 (0.50, CH.sub.3 OH)                          135   (C.sub.3 H.sub.7).sub.2 CHCOVal                                                           149-150                                                                             Ethyl acetate-                                                                         -48.8°                                                        hexane   (0.50, CH.sub.3 OH)                          136   (2-benzimidazolyl-S)                                                                      119-120                                                                             CH.sub.2 Cl.sub.2 -ether                                                               -28.4°                                      (C.sub.3 H.sub.7)CHCO      (0.25, CH.sub.3 OH)                          137   PhNHCSIle   --.sup.1)                                                                           --       +18.8°                                                                 (0.485, CHCl.sub.3)                          138   1-NapNHCSIle                                                                              --.sup.2)                                                                           --       +34.2°                                                                 (0.325, CHCl.sub.3)                          139   PhCOGly     --.sup.3)                                                                           --       -11.0°                                                                 (0.50, CH.sub.3 OH)                          140   PhCH.sub.2 OCOAla                                                                         120-121                                                                             ether    +22.9°                                                                 (0.50, CHCl.sub.3)                           141   PhCH.sub.2 OCOLeu                                                                         --.sup.4)                                                                           --       +15.4°                                                                 (0.50, CHCl.sub.3)                           142   1-NapSO.sub.2Leu                                                                           81-82                                                                              Ethyl acetate-                                                                         -40.5°                                                        hexane   (0.50, CHCl.sub.3)                           143   PhCOLeu     162-163                                                                             Ethyl acetate-                                                                         -30.4°                                                        hexane   (0.50, CH.sub.3 OH)                          144   (C.sub.3 H.sub.7).sub.2 CHCOLeu                                                           107-108                                                                             Ethyl acetate-                                                                         +2.6°                                                         hexane   (0.50, CHCl.sub.3)                           145   (C.sub.3 H.sub.7).sub.2 CHCOGly                                                            68-69                                                                              Ethyl acetate-                                                                         +42.8°                                                        hexane   (0.50, CHCl.sub.3)                           146   PhCOIle     188-190                                                                             Ethyl acetate-                                                                         +45.4°                                                        hexane   (0.26, CHCl.sub.3)                           147   Ph(CH.sub.2).sub.3 CO                                                                     --.sup.5)                                                                           --       -17.4°                                                                 (0.665, CHCl.sub.3)                          148   (C.sub.3 H.sub.7).sub.2 CHCOPhe                                                           141-142                                                                             Ethyl acetate-                                                                         -19.1°                                                        hexane   (0.50, CH.sub.3 OH)                          149   (C.sub.3 H.sub.7).sub.2 CHCOIle                                                           143-144                                                                             Ethyl acetate-                                                                         -41.7°                                                        hexane   (0.50, CH.sub.3 OH)                          __________________________________________________________________________     DMSO: dimethyl sulfoxide, DMF: N,Ndimethylformamide, Ph: phenyl, 1Nap:        1naphtyl, tBu: tert.butyl, Ile: (L)isoleucine, Leu: (L)leucine, Ala:          (L)alanine, Gly: glycine, Val: (L)valine, Trp: (L)tryptophan, Phe:            (L)phenylalanine,                                                             Note 1) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 0.8-1.2(7H, m), 1.3-1.5(1H, m),              1.8-2.0(1H, m), 3.23(1H, dd, J=6.6&15.0Hz), 3.34(1H, dd, J=6.0&15.0Hz),       4.77(1H, q, J=6.6&13.0Hz), 4.91(1H, t, J=8.0Hz), 6.65(1H, d, J=6.6Hz),        6.73(1H, d, J=8.4Hz), 7.0-7.4(9H, m), 7.57(1H, d, J=8.4Hz), 8.18(1H, broa     s), 9.60(1H, s).                                                              Note 2) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 0.6-1.3(8H, m), 1.7-1.9(1H, m), 3.26(2H,     dd, J=4.8&6.4Hz), 4.70(1H, q, J=6.6&13.0Hz), 4.88(1H, t, J=8.4Hz),            6.23(1H, d, J=8.4Hz), 6.62(1H, d, J=7.0Hz), 7.1-8.3(14H, m), 9.58(1H, s).     Note 3) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 3.30(2H, d, J=7.0Hz), 4.07(2H, d,            J=5.0Hz), 4.76(1H, q, J=7.0Hz), 6.98(1H, d, J=2.0Hz), 7.01(1H, s),            7.07(1H, dt, J=1.0&8.0Hz), 7.17(1H, dt, J=1.0&8.0Hz), 7.30(1H, t,             J=7.0Hz), 7.41(1H, t, J=7.0Hz), 7.43(1H, d, J=7.0Hz), 7.45(2H, d,             J=8.0Hz), 7.54(1H, d, J=7.0Hz), 7.73(2H, d, J=8.0Hz), 8.28(1H, s),            9.61(1H, s).                                                                  Note 4) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 0.89(6H, d, J=6.0Hz), 1.45-1.50(1H, m),      1.56-1.66(2H, m), 3.28(2H, t, J=7.0Hz), 4.18-4.28(1H, m), 4.74(1H, q,         J=6.0Hz), 5.04(2H, s), 5.12(1H, d, J=9.0Hz), 6.68(1H, d, J=6.0Hz),            6.95(1H, s), 7.11(1H, dt, J=1.0&7.0Hz), 7.19(1H, dt, J=1.0&7.0Hz),            7.31(1H, d, J=1.0Hz), 7.34(5H, s), 7.57(1H, d, J=8.0Hz), 8.08(1H, s),         9.60(1H, s).                                                                  Note 5) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 1.93(2H, quintet, J=7.6Hz), 2.18(2H, t,      J=7.6Hz), 2.61(2H, t, J=7.6Hz), 3.24(1H, dd, J=15.0&7.0Hz), 3.38(1H, dd,      J=15.0&5.4Hz), 4.83(1H, m), 6.03(1H, d, J=4.0Hz), 6.90-7.30(8H, m),           7.60(1H, d, J=7.8Hz), 8.19(1H, broad s), 9.62(1H, s).                    

Examples 150 through 164

The same procedure as in Example 98 was followed to yield the compoundslisted in Table 11.

                                      TABLE 11                                    __________________________________________________________________________     ##STR36##                                                                    Example                        Melting                                                                             Recrystallization                                                                      Optical Rotation                No    R.sup.4 R.sup.1          Point (°C.)                                                                  Solvent   α!.sub.D (c,             __________________________________________________________________________                                                  solvent)                        150   tBuOCO                                                                                 ##STR37##       107-108                                                                             Ethyl acetate- hexane                                                                  -25.7° (0.49, DMSO)      151   PhCH.sub.2 OCO                                                                        CH.sub.3         164-165                                                                             Ethyl acetate                                                                          -26.7°                                                                 (0.305, DMSO)                   152   PhCH.sub.2 OCO                                                                        CH.sub.2 Ph      138-139                                                                             Ethyl acetate-                                                                         -47.4°                                                        hexane   (0.34, DMSO)                    153   1-NapSO.sub.2                                                                         CH.sub.3         150-151                                                                             Ethyl acetate-                                                                         +36.7°                                                        hexane   (0.45, DMSO)                    154   1-NapSO.sub.2                                                                         CH.sub.2 Ph      138-139                                                                             Ethyl acetate-                                                                         -24.3°                                                        hexane   (0.595, DMSO)                   155   PhCH.sub.2 OCO                                                                         ##STR38##        81-82                                                                              Ethyl acetate- hexane                                                                  +27.7° (0.33,                                                          CHCl.sub.3)                     156   PhCH.sub.2 OCO                                                                         ##STR39##       103-104                                                                             Ethyl acetate- hexane                                                                  -40.0° (0.37, DMSO)      157   PhCH.sub.2 OCO                                                                         ##STR40##       155-156                                                                             Ethyl acetate- hexane                                                                  -44.6° (0.315,                                                         DMSO)                           158   1-NapSO.sub.2                                                                          ##STR41##       --.sup.1)                                                                           --       -20.4° (0.305,                                                         CHCl.sub.3)                     159   1-NapSO.sub.2                                                                          ##STR42##       117-118                                                                             Ethyl acetate- hexane                                                                  -16.4° (0.45, DMSO)      160   PhCH.sub.2 OCO                                                                        CH(CH.sub.3).sub.2                                                                             122-123                                                                             Ethyl acetate-                                                                         +4.2°                                                         hexane   (0.29, DMSO)                    161   PhCH.sub.2 OCO                                                                        CH.sub.2 CH(CH.sub.3).sub.2                                                                    157-158                                                                             Ethyl acetate-                                                                         -29.5°                                                        hexane   (0.35, DMSO)                    162   1-NapSO.sub.2                                                                         CH(CH.sub.3).sub.2                                                                             145-146                                                                             Ethyl acetate-                                                                         +24.3°                                                        hexane   (0.515, DMSO)                   163   1-NapSO.sub.2                                                                         CH.sub.2 CH(CH.sub.3).sub.2                                                                    155-156                                                                             Ethyl acetate-                                                                         +12.9°                                                        hexane   (0.82, DMSO)                    164   PhCH.sub.2 OCO                                                                        H                169-171                                                                             Ethyl acetate-                                                                         -10.5°                                                        hexane   (0.50, CHCl.sub.3)              __________________________________________________________________________     DMSO: dimethyl sulfoxide, Ph: phenyl, 1Nap: 1naphthyl, tBu: tert.butyl,       Note 1) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 0.4-0.7(6H, m), 0.7-1.0(1H, m),              1.0-1.2(1H, m), 1.5-1.8(1H, m), 2.58(1H, dd, J=7.0&14.0Hz), 2.74(1H, dd,      J=6.6&14.0Hz), 3.59(1H, dd, J=5.6&7.8Hz), 4.38(1H, q, J=6.6&13.6Hz),          5.81(1H, d, J=8.0Hz), 6.5-7.0(6H, m), 7.4-7.7(3H, m), 7.91(1H, d,             J=8.0Hz), 8.05(1H, d, J=8.0Hz), 8.23(1H, d, J=7.4Hz), 8.68(1H, d,             J=8.0Hz), 9.16(1H, s).                                                   

Examples 165 through 169

The same procedure as in Example 98 was followed to yield the compoundslisted in Table 12.

                                      TABLE 12                                    __________________________________________________________________________     ##STR43##                                                                    Example                     Melting                                                                             Recrystallization                                                                      Optical Rotation                   No    R             R.sup.1 Point (°C.)                                                                  Solvent   α!.sub.D (c,                __________________________________________________________________________                                               solvent)                           165   (PhCH.sub.2).sub.2 CHCO                                                                     CH.sub.2 Ph                                                                           113-114                                                                             CH.sub.2 Cl.sub.2 -                                                                    +29.0°                                                        isopropyl ether                                                                        (0.59, CHCl.sub.3)                 166   PhCH.sub.2 OCOLeuLeu                                                                        H       110-111                                                                             Ethyl acetate-                                                                         -51.2°                                                        hexane   (0.50, CH.sub.3 OH)                167   (PhCH.sub.2).sub.2 CHCO                                                                     CH.sub.2 CH.sub.3                                                                     141-142                                                                             CH.sub.2 Cl.sub.2 -                                                                    +19.3°                                                        hexane   (0.51, CHCl.sub.3)                 168   (PhCH.sub.2).sub.2 CHCO                                                                     CH(CH.sub.3).sub.2                                                                    139-140                                                                             CH.sub.2 Cl.sub.2 -                                                                    +40.4°                                                        hexane   (0.53, CHCl.sub.3)                 169   (PhCH.sub.2).sub.2 CHCO                                                                     CH.sub.3                                                                              136-137                                                                             CH.sub.2 Cl.sub.2 -                                                                    -3.9°                                                         hexane   (0.55, CHCl.sub.3)                 __________________________________________________________________________     Leu: (L)leucine, Ph: phenyl                                              

Example 170

The same procedure as in Example 98 was followed to yieldN-benzyloxycarbonyl-(L)-isoleucyl-(D)-tryptophanal and recrystallizedfrom ethyl acetate-hexane. Melting point 163°-164° C.

α!_(D) =+37.2° (c0.635, DMSO)

Example 171

The same procedure as in Example 98 was followed to yieldN-(1-naphthylsulfonyl)-(L)-isoleucyl-(D)-tryptophanal as an amorphoussolid.

α!_(D) =-39.3° (c0.30, CHCl₃)

NMR(δ ppm in CDCl₃): 0.50 (3H,d,J=6.8 Hz), 0.62 (3H,t,J=7.6 Hz), 0.7-0.9(1H,m), 1.2-1.4 (1H,m), 1.5-1.8 (1H,m), 2.90 (1H,dd,J=7.4&14.8 Hz), 3.12(1H,dd,J=8.0&14.8 Hz), 3.53 (1H,dd,J=5.4&7.8 Hz), 4.36 (1H,dd,J=6.2&13.0Hz), 5.47 (1H,d,J=8.0 Hz), 6.50 (1H,d,J=6.6 Hz), 7.0-8.3 (12H,m), 8.63(1H,d,J=8.4 Hz), 9.19 (1H,s).

Examples 172 through 193

The same procedure as in Example 98 was followed to yield the compoundslisted in Table 13 and 14.

                                      TABLE 13                                    __________________________________________________________________________     ##STR44##                                                                    Example                   Melting                                                                             Recrystallization                                                                      Optical Rotation                     No    R             R.sup.1                                                                             Point (°C.)                                                                  Solvent   α!.sub.D (c,                  __________________________________________________________________________                                             solvent)                             172   (C.sub.3 H.sub.7).sub.2 CHCO                                                                PhCH.sub.2                                                                          108-109                                                                             CH.sub.2 Cl.sub.2 -ether-                                                              +88.9°                                                        isopropyl ether                                                                        (0.5, CHCl.sub.3)                    173   Ph(CH.sub.2).sub.3 CO                                                                       PhCH.sub.2                                                                          112-113                                                                             AcOEt-ether-                                                                           +53.7°                                                        hexane   (0.535, CHCl.sub.3)                  174   PhCH.sub.2 OCOLeu                                                                           H      93-94                                                                              AcOEt-hexane                                                                           +2.6°                                                                  (0.23, CHCl.sub.3)                   175   1-NapSO.sub.2LeuTrp                                                                         H     177-178                                                                             AcOEt    -13.1°                                                                 (0.235, DMSO)                        __________________________________________________________________________     Leu: (L)leucine, Trp: (L)tryptophan, Ph: phenyl, 1Nap: 1naphthyl, AcOEt:      ethyl acetate                                                            

                                      TABLE 14                                    __________________________________________________________________________     ##STR45##                                                                    Example             Melting                                                                             Recrystallization                                                                      Optical Rotation                           No.   R             Point (°C.)                                                                  Solvent   α!.sub.D (c, solvent)               __________________________________________________________________________    176   (CH.sub.3).sub.2 CHCH.sub.2 CH.sub.2                                                         50-51                                                                              AcOEt-hexane                                                                           -34.1°                                    CO                           (0.5, CH.sub.3 OH)                         177   cyclohexyl-CO 138-139                                                                             AcOEt-hexane                                                                           -41.5°                                                                 (0.5, CH.sub.3 OH)                         178   PhCO          134-135                                                                             AcOEt-hexane                                                                           -97.2°                                                                 (0.5, CH.sub.3 OH)                         179   Ph(C.sub.2 H.sub.5)CHCO                                                                     --.sup.1)                                                                           AcOEt-hexane                                                                           +12.6                                                                         (0.585, CHCl.sub.3)                        180   (PhCH.sub.2) (4-CH.sub.3                                                                    --.sup.2)      +32.3°                                    C.sub.6 H.sub.4)CH.sub.2 !CHCO                                                                             (0.475, CHCl.sub.3)                        181   PhCH.sub.2 CH.sub.2COVal                                                                    161-162                                                                             AcOEt-hexane                                                                           -72.1°                                                                 (0.50, CH.sub.3 OH)                        182   (PhCH.sub.2).sub.2 CHCOVal                                                                  156-157                                                                             AcOEt-hexane                                                                           -44.0°                                                                 (0.50, CH.sub.3 OH)                        183   (PhCH.sub.2) (2-CH.sub.3 O                                                                  136-138                                                                             AcOEt-hexane                                                                           +15.5°                                    C.sub.6 H.sub.4)CH.sub.2 !CHCO                                                                             (0.475, CHCl.sub.3)                        184   (PhCH.sub.2) (4-CH.sub.3 O                                                                  --.sup.3)      +15.7°                                    C.sub.6 H.sub.4)CH.sub.2 !CHCO                                                                             (0.54, CHCl.sub.3)                         185    (4-PhCONHC.sub.6 H.sub.4)                                                                  190-191                                                                             AcOEt-hexane                                                                           -69.9°                                    CH.sub.2 !(PhCH.sub.2)CHCO   (0.405, CHCl.sub.3)                        186    (4-CH.sub.3 CONHC.sub.6 H.sub.4)                                                           124-125                                                                             AcOEt-hexane                                                                           -32.4°                                    CH.sub.2 !(PhCH.sub.2)CHCO   (0.225, DMSO)                              187    (4-TolSO.sub.2 NHC.sub.6 H.sub.4)                                                          --.sup.4)      +22.2°                                    CH.sub.2 !(PhCH.sub.2)CHCO   (0.415, CHCl.sub.3)                        188     4-(C.sub.2 H.sub.5 O).sub.2 P(O)                                                          --.sup.5)      -5.8°                                     CH.sub.2 !C.sub.6 H.sub.4 NHCO!(Ph                                                                         (0.665, CHCl.sub.3)                              CH.sub.2)CHCO                                                           189   (C.sub.2 H.sub.5 OOC)(PhCH.sub.2)C                                                          --.sup.6)      +22.3°                                    HCO                          (0.66, CHCl.sub.3)                         190    (PhCH.sub.2).sub.2 N                                                                       --.sup.7)      +6.6°                                     CO!(PhCH.sub.2).sub.2 CHCO   (0.90, CHCl.sub.3)                         191   (PhCH.sub.2 NH                                                                              --.sup.8)      -14.2°                                    CO)(PhCH.sub.2)CHCO          (0.94, DMSO)                               192   Ph.sub.2 CHCO 172-173                                                                             AcOEt-hexane                                                                           -8.0°                                                                  (0.37, DMSO)                               193   (4-oxo-4H-1-  120-121                                                                             AcOEt-hexane                                                                           -69.8°                                    benzopyran-2-yl)-COIle       (0.50, CH.sub.3 OH)                        __________________________________________________________________________     Leu: (L)leucine, Val: (L)valine, Ph: phenyl, Tol: 4tolyl, AcOEt: ethyl        acetate                                                                       Note 1) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 0.86(3H, t, J=7.4Hz), 1.80(1H, m),           2.17(1H, m), 3.13-3.37(3H, m), 4.64(1H, q, J=6.6Hz), 6.06(1H, d, J=5.8Hz)     6.75(1H, d, J=2.0Hz), 7.00-7.40(7H, m), 7.55(1H, d, J=7.8Hz), 8.07(1H,        broad s), 9.53(1H, s).                                                        Note 2) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 2.27&2.30(3H, each s), 2.46-2.66(1H, m),     2.72-3.24(6H, m), 5.53-5.70(1H, m), 6.37-6.52(1H, m), 6.88-7.50(13H, m),      7.95(1H, broad), 9.19&9.21(1H, each s).                                       Note 3) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 2.35-3.20(7H, m), 3.75&3.77(3H, each s),     4.42-4.58(1H, m), 5.50-5.62(1H, m), 6.32&6.38(1H, each d, J=2.4Hz),           6.72-6.88(2H, m), 7.00-7.60(11H, m), 7.92(1H, broad s), 9.19&9.25(1H, eac     broad s).                                                                     Note 4) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 2.30(3H, s), 2.5-3.1(7H, m), 4.2-4.4(1H,     m), 5.72(1H, d, J=6.6Hz), 6.25(1H, d, J=1.8Hz), 6.8-7.4(15H, m), 7.59(2H,     d, J=8.2Hz), 8.32(1H, broad s), 9.13(1H, s).                                  Note 5) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 1.21(3H, t, J=7.0Hz), 1.22(3H, t,            J=7.0Hz), 3.0-3.3(6H, m), 3.5-3.7(1H, m), 3.8-4.1(4H, m), 4.5-4.7(1H, m),     6.65&6.71(1H, each d, J=1.6Hz), 7.0-7.6(13H, m), 8.44&8.61(1H, each broad     s), 9.27&9.39(1H, each broad s), 9.42&9.47(1H, each s).                       Note 6) Oil                                                                   NMR (δ ppm in CDCl.sub.3): 1.12(3H, t, J=6.2Hz), 3.1-3.6(5H, m),        4.02(2H, q, J=14.2&6.2Hz), 4.6-4.8(1H, m), 6.81&6.92(1H, each d, J=2.2Hz)     7.0-7.4(9H, m), 7.49&7.59(1H, each d, J=7.4Hz), 8.22(1H, broad s),            9.51&9.54(1H, each s).                                                        Note 7) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 3.0-3.4(4H, m), 3.85(1H, dt,                 J=10.4&4.2Hz), 4.0-4.5(4H, m), 4.6-4.8(1H, m), 6.6-6.8(2H, m),                6.9-7.3(17H, m), 7.4-7.7(2H, m), 8.33&8.38(1H, each s), 9.56(1H, s).          Note 8) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 2.9-3.3(4H, m), 3.54(1H, t, J=7.2Hz),        4.0-4.5(3H, m), 6.9-7.5(15H, m), 8.23(1H, d, J=7.0Hz), 8.29(1H, t,            J=7.0Hz), 9.43&9.47(1H, each s), 10.86(1H, s).                           

Example 194

To a solution of N-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-tryptophanol(1.0 g) and acetyl chloride (0.171 g) in N,N-dimethylformamide (6 ml)was added 4-(N,N-dimethylamino)pyridine (0.28 g) under ice-cooling andstirred for 3 hours at the same temperature. The reaction mixture waspoured on ice-water and extracted with ethyl acetate. The ethyl acetatelayer was washed sequentially with an aqueous citric acid solution,water, an aqueous sodium bicarbonate solution and water, and dried(MgSO₄). After the solvent was distilled off, the residue was subjectedto silica gel column chromatography. O-acetyl compound ofN-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-tryptophanol (shown as ExampleNo. 194 in Table 16) was obtained as an amorphous solid (0.83 g, 76%)from the eluted fraction of ethyl acetate-hexane (2:3, v/v).

NMR (δ ppm in CDCl₃): 0.5-0.9 (7H,m), 1.0-1.2 (1H,m), 1.6-1.8 (1H,m),2.01 (3H,s), 2.53 (1H,dd,J=14.8&6.2 Hz), 2.63 (1H,dd,J=14.8&7.0 Hz),3.52 (1H,dd,J=8.2&5.2 Hz), 3.68 (1H,dd,J=11.4&6.4 Hz), 3.79(1H,dd,J=11.4&6.6 Hz), 4.1-4.3 (1H,m), 5.55 (1H,d,J=8.2 Hz), 6.10(1H,d,J=8.4 Hz), 6.91 (1H,d,J=2.2 Hz), 7.0-7.7 (7H,m), 7.89 (1H,d,J=8.4Hz), 8.02 (1H,d,J=8.2 Hz), 8.22 (1H,dd,J=7.2&1.2 Hz), 8.29 (1H,broad s),8.67 (1H,d,J=8.4 Hz). α!_(D) -31.4° (c 0.39, CHCl₃).

Elemental analysis (for C₂₉ H₃₃ N₃ O₅ S•1/2H₂ O) Calcd.: C, 63.95; H,6.29; N, 7.71 Found: C, 64.17; H, 6.20; N, 7.55

Example 195 through 198

The same procedure as in Example 194 was followed to yield the compoundslisted in Table 15.

                                      TABLE 15                                    __________________________________________________________________________     ##STR46##                                                                    Example                          Melting                                                                             Recrystallization                                                                      Optical Rotation              No    R             R.sup.1                                                                            X       Point (°C.)                                                                  Solvent   α!.sub.D (c,                                                           solvent)                      __________________________________________________________________________    194   1-NapSO.sub.2Ile                                                                            3-Ind                                                                              CH.sub.2 OCO                                                                          --             -31.3°                                     CH.sub.2                                                                           CH.sub.3               (0.39, CHCl.sub.3)            195   1-NapSO.sub.2Ile                                                                            3-Ind                                                                              CH.sub.2 OCO                                                                          --.sup.1)      -27.8°                                     CH.sub.2                                                                           CH.sub.2 CH.sub.3      (0.52, CHCl.sub.3)            196   1-NapSO.sub.2Ile                                                                            3-Ind                                                                              CH.sub.2 OCO                                                                          --.sup.2)      -11.3°                                     CH.sub.2                                                                           Ph                     (0.435, CHCl.sub.3)           197   (PhCH.sub.2).sub.2 C                                                                        3-Ind                                                                              CH.sub.2 OCO                                                                          129-130                                                                             AcOEt-   -7.2°                        HCO           CH.sub.2                                                                           CH.sub.3      hexane   (0.75, DMSO)                  198   1-NapSO.sub.2LeuTrp                                                                         CH.sub.3                                                                           CH.sub.2 OCO                                                                          157-158                                                                             AcOEt-   +55.9°                                          CH.sub.3      hexane   (0.705,                       __________________________________________________________________________                                                    DMSO)                          1-Nap: 1naphthyl, Ile: (L)isoleucine, Trp: (L)tryptophan Ph: phenyl, 3Ind     3indolyl, AcOEt: ethyl acetate                                                Note 1) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 0.5-0.9(7H, m), 1.00(3H, t, J=7.6Hz),        1.0-1.2(1H, m), 1.5-1.8(1H, m), 2.28(2H, q, J=7.6Hz), 2.51(1H, dd,            J=14.6&6.2Hz), 2.61(1H, dd, J=14.6&7.2Hz), 3.53(1H, dd, J=8.0&5.4Hz),         3.68(1H, dd, J=11.4&6.2Hz), 3.79(1H, dd, J=11.4&4.8Hz), 4.1-4.3(1H, m),       5.64(1H, d, J=8.0Hz), 6.14(1H, d, J=8.4Hz), 6.90(1H, d, J=2.0Hz),             7.0-7.7(7H, m), 7.88(1H, d, J=7.8Hz), 8.01(1H, d, J=8.2Hz), 8.21(1H, d,       J=7.2Hz), 8.38(1H , broad s), 8.67(1H, d, J=8.4Hz).                           Note 2) Amorphous solid                                                       NMR (δ ppm in CDCl.sub.3): 0.50(3H, t, J=7.2Hz), 0.59(3H, d,            J=6.8Hz), 0.6-0.9(1H, m), 1.0-1.2(1H, m), 1.5-1.8(1H, m), 2.53(1H, dd,        J=14.6&6.2Hz), 2.64(1H, dd, J=14.6&7.2Hz), 3.57(1H, dd, J=8.4&5.4Hz),         3.87(1H, dd, J=11.4&6.8Hz), 3.97(1H, dd, J=11.4&4.6Hz), 4.2-4.4(1H, m),       5.70(1H, d, J=8.4Hz), 6.19(1H, d, J=8.4Hz), 6.91(1H, d, J=2.4Hz),             7.0-7.6(10H, m), 7.8-8.0(4H, m), 8.17(1H, dd, J=7.4&1.0Hz), 8.40(1H, broa     s), 8.67(1H, d, J =8.6Hz).                                               

    ______________________________________                                        Seguence table                                                                ______________________________________                                        SEQ ID NO  : 1                                                                Sequence length                                                                          : 20                                                               Sequence type                                                                            : Nucleic acid                                                     Strandedness                                                                             : Single                                                           Topology   : Linear                                                           Molecule type                                                                            : Other nucleic acid (chemically synthesized DNA)                  Antisense  : No                                                               Sequence   :                                                                  TTTTCAGGGGGCAGTAAGAT                                                          SEQ ID NO  : 2                                                                Sequence length                                                                          : 28                                                               Sequence type                                                                            : Nucleic acid                                                     Strandedness                                                                             : Single                                                           Topology   : Linear                                                           Molecule type                                                                            : Other nucleic acid (chemically synthesized DNA)                  Antisense  : No                                                               Sequence   :                                                                  CCGGATCCGGCTTTTTAGGATTGGTCTA                                                  SEQ ID NO  : 3                                                                Sequence length                                                                          : 20                                                               Sequence type                                                                            : Nucleic acid                                                     Strandedness                                                                             : Single                                                           Topology   : Linear                                                           Molecule type                                                                            : Other nucleic acid (chemically synthesized DNA)                  Antisense  : Yes                                                              Sequence   :                                                                  GGGGGCTGGTAGACTGAAGA                                                          SEQ ID NO  : 4                                                                Sequence length                                                                          : 28                                                               Sequence type                                                                            : Nucleic acid                                                     Strandedness                                                                             : Single                                                           Topology   : Linear                                                           Molecule type                                                                            : Other nucleic acid (chemically synthesized DNA)                  Antisense  : Yes                                                              Sequence   :                                                                  CCGGATCCATTCCTCCCATGCATGCGCC                                                  SEQ ID NO  : 5                                                                Sequence length                                                                          : 12                                                               Sequence type                                                                            : Nucleic acid                                                     Strandedness                                                                             : Single                                                           Topology   : Linear                                                           Molecule type                                                                            : Other nucleic acid (chemically synthesized DNA)                  Antisense  : No                                                               Sequence   :                                                                  CCCGGATCCGGG                                                                  ______________________________________                                    

What is claimed is:
 1. A compound of the formula (I): ##STR47## whereinR¹ is a C₁₋₆ alkyl group which may be substituted by an indolyl group oran aryl group selected from the group consisting of phenyl, naphthyl,anthryl, phenanthryl and acenaphthylenyl;R² is a hydrogen atom, or(A) anarylalkyl group said arylalkyl group being unsubstituted or substitutedby 1 to 3 substituents selected from the group consisting of(i) linearor branched aliphatic hydrocarbon groups selected from the groupconsisting of C₁₋₁₀ alkyl groups, C₂₋₁₀ alkenyl groups and alkynylgroups selected from the group consisting of ethynyl, 1-propynyl,2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl,3-pentynyl, 4-pentynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl and5-hexynyl, (ii) saturated or unsaturated alicyclic hydrocarbon groupsselected from the group consisting of cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, bicyclo 2.2.1!heptyl,bicyclo 2.2.2!octyl, bicyclo 3.2.1!octyl, bicyclo 3.2.2!nonyl, bicyclo3.3.1!nonyl, bicyclo 4.2.1!nonyl, bicyclo 4.3.1!decyl,2-cyclopenten-1-yl, 3-cyclopenten-1-yl, 2-cyclohexen-1-yl,3-cyclohexen-1-yl, 2,4-cyclopentadien-1-yl, 2,4-cyclohexadien-1-yl and2,5-cyclohexadien-1-yl, (iii) aryl groups selected from the groupconsisting of phenyl, naphthyl, anthryl, phenanthryl, acenaphthylenyl,(iv) aromatic monocyclic heterocyclic groups selected from the groupconsisting of furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl,isothiazolyl, imidazolyl, pyrazolyl, 1,2,3-oxadiazolyl,1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, lurazanyl, 1,2,3-thiadiazolyl,1,2,4-thiadiazolyl, 1,3,4-thiadiazolyl, 1,2,3-triazolyl,1,2,4-triazolyl, tetrazolyl, pyridyl, pyridazinyl, pyrimidinyl,pyrazinyl and triazinyl, and aromatic condensed heterocyclic groupsselected from the group consisting of benzofuranyl, isobenzofuranyl,benzo b!thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl,benzoxazolyl, 1,2-benzisoxazolyl, benzothiazolyl, 1,2-benzisothiazolyl,1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl,quinoxalinyl, phthalazinyl, naphthylizinyl, purinyl, pteridinyl,carbazolyl, α-carbolinyl, β-carbolinyl, γ-carbolinyl, acridinyl,phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thiantherenyl,phenanthridinyl, phenanthrolinyl, indolizinyl, pyrrolo1,2-b!pyridazinyl, pyrazolo 1,5-a!pyridyl, imidazo 1,2-a!pyridyl,imidazo 1,5-a!pyridyl, imidazo 1,2-b!pyridazinyl, imidazo1,2-a!pyrimidinyl, 1,2,4-triazolo 4,3-a!pyridyl and 1,2,4-triazolo4,3-b!pyridazinyl, (v) halogens, (vi) nitro groups, (vii) optionallysubstituted amino groups selected from the group consisting of amino,methylamino, dimethylamino, ethylamino, diethylamino, dibutylamino,diallylamino, cyclohexylamino, phenylamino, N-methyl-N-phenylamino,acetylamino, propionylamino and benzoylamino, (viii) acyl groupsselected from the group consisting of formyl, acetyl, propionyl,butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, hexanoyl, heptanoyl,octanoyl, cyclobutanoyl, cyclopentanoyl, cyclohexanoyl, cycloheptanoyl,crotonyl, 2-cyclohexenecarbonyl, benzoyl, nicotinoyl, (ix) hydroxylgroups, C₁₋₁₀ alkoxy groups, C₁₋₁₀ alkenyloxy groups, phenyl-C₁₋₄alkyloxy groups, C₂₋₄ alkanoyloxy groups and aryloxy groups selectedfrom the group consisting of phenoxy and 4-chlorophenoxy, (x) thiolgroups, C₁₋₁₀ alkylthio groups, phenyl-C₁₋₄ alkylthio groups and C₂₋₄alkanoylthio groups, and (xi) optionally esterified carboxyl-groups or(B) an aliphatic hydrocarbon group selected from the group consisting oflinear or branched saturated aliphatic hydrocarbon having 1 to 8 carbonatoms, unsaturated aliphatic hydrocarbon having 2 to 8 carbon atoms,saturated alicyclic hydrocarbon having 3 to 7 carbon atoms, unsaturatedalicyclic hydrocarbon having 5 to 7 carbon atoms and groups resultingfrom binding of (a) a saturated alicyclic hydrocarbon having 3 to 7carbon atoms or an unsaturated alicyclic hydrocarbon having 5 to 7carbon atoms and (b) a saturated aliphatic hydrocarbon having 4 to 9carbon atoms, said hydrocarbon group being unsubstituted or substitutedby 1 to 3 substituents selected from the group consisting of(i)halogens, (ii) nitro groups, (iii) optionally substituted amino groupsselected from the group consisting of amino, methylamino, dimethylamino,ethylamino, diethylamino, dibutylamino, diallylamino, cyclohexylamino,phenylamino, N-methyl-N-phenylamino, acetylamino, propionylamino andbenzoylamino, (iv) acyl groups selected from the group consisting offormyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl,pivaloyl, hexanoyl, heptanoyl, octanoyl, cyclobutanoyl, cyclopentanoyl,cyclohexanoyl, cycloheptanoyl, crotonyl, 2-cyclohexenecarbonyl, benzoyl,nicotinoyl, (v) hydroxyl groups, C₁₋₁₀ alkoxy groups, C₁₋₁₀ alkenyloxygroups, phenyl-C₁₋₄ alkyloxy groups, C₂₋₄ alkanoyloxy groups and aryloxygroups selected from the group consisting of phenoxy and4-chlorophenoxy, (vi) thiol groups, C₁₋₁₀ alkylthio groups, phenyl-C₁₋₄alkylthio groups and C₂₋₄ alkanoylthio groups, and (vii) optionallyesterified carboxyl groups selected from the group consisting ofcarboxy, those resulting from binding of a carboxyl group and C₁₋₆ alkylgroup, those resulting from binding of a carboxyl group and a C₃₋₆alkenyl group, benzyloxycarbonyl and phenethyloxycarbonyl; R⁴ is (1) aC₂₋₆ alkanoyl group substituted by 1 to 3 C₉₋₁₂ aryl groups, or (2) agroup of the formula: --SO₂ R⁷, --CONHR⁸ or --CSNHR⁹, wherein each ofR⁷, R⁸ and R⁹ is (i) an aryl group having more than 9 carbon atomsselected from the group consisting of naphthyl, anthryl, phenanthryl andacenaphthylenyl, or (ii) a C₁₋₅ alkyl group; X is a group of theformula: --CHO or CH₂ OB wherein B is a hydrogen atom or --OB is aprotected hydroxyl group selected from the group consisting of an alkoxygroup having 1 to 10 carbon atoms, an alkenyloxy group having 1 to 10carbon atoms, a phenyl-C₁₋₄ alkyloxy group, an alkanoyloxy group having2 to 4 carbon atoms, and an aryloxy group selected from the groupconsisting of phenoxy and 4-chlorophenoxy;or a pharmaceuticallyacceptable salt thereof.
 2. The compound according to claim 1 wherein R¹is an indolyl-C₁₋₆ alkyl group.
 3. The compound according to claim 1wherein R¹ is a naphthyl-C₁₋₆ alkyl group.
 4. The compound according toclaim 1 wherein R¹ is a phenyl-C₁₋₆ alkyl group.
 5. The compoundaccording to claim 1 wherein R² is a branched C₃₋₆ alkyl group.
 6. Thecompound according to claim 1 wherein R² is a phenyl-C₁₋₆ alkyl group.7. The compound according to claim 1 wherein X is --CHO or --CH₂ OH. 8.The compound according to claim 1 wherein R¹ is a C₁₋₆ alkyl group whichmay be substituted by indolyl; R² is a C₁₋₆ alkyl group; R⁴ is anaphthylsulfonyl or dibenzylacetyl; X is --CHO or --CH₂ OH.
 9. Thecompound according to claim 1 which isN-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-alaninal.
 10. The compoundaccording to claim 1 which isN-(1-naphthylsulfonyl)-(L)-isoleucyl-(L)-tryptophanol.
 11. Apharmaceutical composition which comprises a compound as claimed inclaim 1 or a pharmaceutically acceptable salt thereof, and apharmaceutically acceptable carrier, excipient or diluent.
 12. A methodof producing the compound as defined in claim 1 wherein R⁴ is (1) a C₂₋₆alkanoyl group substituted by 1 to 3 C₉₋₁₂ aryl groups, or (2) a groupof the formula: --SO₂ R⁷ wherein R⁷ is (i) an aryl group having morethan 9 carbon atoms selected from the group consisting of naphthyl,anthryl, phenanthryl and acenaphthylenyl, or (ii) a C₁₋₆ alkyl group, ora pharmaceutically acceptable salt thereof, which comprises subjecting acompound of the formula: ##STR48## wherein R² is as defined in claim 1and R^(4') is a C₂₋₅ alkanoyl group substituted by 1 to 3 C₉₋₁₂ arylgroups or a group of the formula: --SO₂ R⁷ wherein R⁷ is an aryl grouphaving more than 9 carbon atoms selected from the group consisting ofnaphthyl, anthryl, phenanthryl and acenaphthylenyl or a C₁₋₆ alkylgroup, or its reactive derivative, with a compound of the formula:##STR49## wherein R¹ is as defined in claim 1, and if desired,subjecting the compound (I) wherein X is CH₂ OH to oxidation reaction ora reaction of protecting a hydroxyl group.
 13. A method of producing thecompound as defined in claim 1 or a pharmaceutically acceptable saltthereof, which comprises reacting a compound of the formula: ##STR50##wherein R² is as defined in claim 1 and M is a protecting group of aminogroup, or its reactive derivative, with a compound of the formula:##STR51## wherein R¹ is as defined in claim 1, and subjecting theobtained compound to deprotecting reaction, and then to acylationreaction, sulfonylation reaction, carbamoylation reaction orthiocarbamoylation reaction, and if desired, subjecting the compound (I)wherein X is CH₂ OH to oxidation reaction or a reaction of protecting ahydroxyl group.